Carefully read this manual in its entirety before working on the engine. Good knowledge of all compo- nents making up the engine and all the procedures to ...
WORKSHOP MANUAL. www.betamotor.com. Table of contents. ... Use Betamotor spare parts only. For their codes refer to the spare parts manual for the specific vehicle...
RACE EDITION 250 / 300 2 Stroke 2020-2021 WORKSHOP MANUAL www.betamotor.com TABLE OF CONTENTS INTRODUCTION 2 ENGINE TECHNICAL SPECIFICATIONS 4 SPECIAL EQUIPMENT 5 1 ENGINE REMOVAL FROM VEHICLE 6 2 ENGINE DISASSEMBLY 17 2.1 2.2 2.3 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.5 2.5.1 2.5.2 2.6 2.6.1 2.6.2 2.6.3 2.6.4 2.6.5 2.7 CLUTCH/GEAR OIL DRAIN............................................ 17 REMOVAL OF CLUTCH CONTROL ROD AND PINION SPACER ............................................................................ 17 REMOVAL OF PISTON, CYLINDER AND HEAD......... 18 REMOVAL OF IGNITION UNIT..................................... 21 REMOVAL OF FLYWHEEL COVER............................................ 21 STATOR REMOVAL......................................................................... 21 REMOVAL OF FLYWHEEL............................................................ 22 REMOVAL OF PICK-UP UNIT..................................................... 22 REMOVAL OF ELECTRIC IGNITION............................. 23 REMOVAL OF START MOTOR.................................................... 24 REMOVAL OF BENDIX COUPLING.......................................... 24 REMOVAL OF COOLANT LIQUID PUMP, CLUTCH UNIT, MAIN GEAR, CENTRIFUGAL UNIT, GEARSHIFT ORGANS, KICKSTART .................................................... 25 REMOVAL OF COOLANT LIQUID PUMP.............................. 28 REMOVAL OF CENTRIFUGAL UNIT AND LEVERAGE....... 29 DISASSEMBLY OF CLUTCH UNIT AND COUNTERSHAFT COUNTERWEIGHT........................................................................ 32 PEDAL KICKSTART - OPTIONAL................................................ 35 EXTERNAL GEARSHIFT UNIT.................................................... 37 INTAKE SYSTEM.............................................................. 38 2.8 2.8.1 2.8.2 2.8.3 2.8.4 2.9 2.9.1 2.9.2 CRANKSHAFT, GEARBOX UNIT AND INTERNAL GEARSHIFT...................................................................... 39 OPENING THE CRANKCASE..................................................... 39 COUNTERWEIGHT SUPPORT SHAFT.....................................40 CRANKSHAFT.................................................................................. 40 INTERNAL GEARSHIFT UNIT AND COMPLETE GEARBOX.41 DISASSEMBLY OF PARTS FROM CRANKCASES........43 RIGHT CRANKCASE HALF..........................................................43 LEFT CRANKCASE HALF..............................................................45 3 ENGINE CHECKS AND ASSEMBLY 46 3.1 3.1.1 3.1.2 3.2 3.3 3.4 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.5 3.6 3.6.1 3.6.2 3.7 3.7.1 3.7.2 3.8 3.8.1 3.8.2 3.8.3 3.8.4 3.8.5 3.8.6 3.8.7 3.8.8 3.9 3.9.1 3.9.2 3.9.3 3.9.4 CRANKCASE HALF.........................................................46 APPLICATION OF RIGHT CRANKCASE HALF PARTS......... 47 APPLICATION OF LEFT CRANKCASE HALF PARTS............49 CONNECTING ROD AND ENGINE SHAFT CHECK.... 50 ASSEMBLY OF COMPLETE CRANKSHAFT................. 51 GEAR UNIT: CHECKS AND REASSEMBLY.................. 52 GEARBOX UNIT CHECK ............................................................. 52 PRIMARY UNIT ASSEMBLY......................................................... 53 SECONDARY UNIT ASSEMBLY.................................................. 54 CHECKING THE FORKS, FORK PINS AND DESMODROMIC DEVICE.............................................................................................. 55 GEARBOX AND INTERNAL GEARSHIFT ASSEMBLY.......... 57 COUNTERWEIGHT SUPPORT SHAFT.....................................60 CLOSING THE ENGINE CRANKCASE.......................... 61 EXTERNAL GEARSHIFT..................................................62 CHECKING THE COMPLETE DRIVE SHAFT.........................62 EXTERNAL GEARSHIFT ASSEMBLY.........................................64 KICKSTARTER DEVICE - OPTIONAL.............................65 CHECKING THE KICKSTART SHAFT UNIT AND ASSEMBLY...65 ASSEMBLY OF KICKSTARTER DEVICE.....................................66 COUNTERWEIGHT, PRIMARY GEAR AND CLUTCH UNIT.................................................................................. 68 INSPECTION OF COUNTERWEIGHT AND PRIMARY GEAR...................................................................68 APPLICATION OF PRIMARY GEAR AND COUNTERWEIGHT.............................................................68 CHECKING THE CLUTCH CASE, ROLLER BEARING AND INTERNAL CENTRE BEARING................................................... 70 CHECKING THE CLUTCH DISCS.............................................. 71 CHECKING THE SPRINGS.......................................................... 71 CHECKING THE CLUTCH DRUM AND CAP........................ 72 CHECKING THE THRUST BEARING DEVICE....................... 72 CLUTCH UNIT ASSEMBLY.......................................................... 73 COOLANT LIQUID PUMP AND CENTRIFUGAL UNIT...76 CHECKING THE PUMP UNIT AND DISASSEMBLY, CENTRIFUGAL UNIT AND IDLER UNIT ................................ 77 CENTRIFUGE UNIT GROUP ASSEMBLY .............................. 78 PUMP UNIT ASSEMBLY ............................................................. 81 ASSEMBLY OF COMPLETE CLUTCH COVER AND PUMP UNIT..................................................................................... 81 3.10 3.10.1 3.10.2 3.11 3.11.1 3.11.2 3.12 3.12.1 3.12.2 3.12.3 3.12.4 3.12.5 3.12.6 3.12.7 3.12.8 3.12.9 3.13 3.14 ELECTRIC IGNITION UNIT ............................................84 BENDIX COUPLING CHECKS....................................................84 IGNITION UNIT COUPLING TO ENGINE .............................84 IGNITION SYSTEM..........................................................85 IGNITION SYSTEM CHECK ........................................................86 COUPLING OF IGNITION SYSTEM TO CRANKCASE........86 THERMAL UNIT..............................................................89 CHECKING THE PISTON AND ELASTIC BANDS................89 CYLINDER CHECK.........................................................................90 PISTON CYLINDER COUPLING PLAY..................................... 91 CHECKS AND EXHAUST VALVE UNIT DISASSEMBLY....... 91 EXHAUST VALVE ............................................................................93 UNIT ASSEMBLY............................................................................93 PISTON, PIN BOLT, ELASTIC BANDS AND CYLINDER ASSEMBLY .......................................................................................95 CHECK OF CRANKCASE/CYLINDER GASKET THICKNESS... 97 HEAD APPLICATION.....................................................................98 EXHAUST VALVE ............................................................................99 ADJUSTMENT................................................................................. 99 CHECK OF INTAKE UNIT AND ASSEMBLY...............103 INSERTION OF CLUTCH ROD AND PINION SPACER...........................................................................105 4 ENGINE REASSEMBLY IN THE VEHICLE 106 TABLE OF ENGINE COMPONENTS TIGHTENING TORQUES 116 TABLE OF FRAME/ENGINE TIGHTENING TORQUES 118 TABLE OF SUPERSTRUCTURE TIGHTENING TORQUES 118 RECOMMENDED ENGINE MAINTENANCE 119 TABLE OF CONTENTS ENGLISH INTRODUCTION www.betamotor.com INTRODUCTION This publication is intended for workshops specialised in repairing mopeds and motorcycles. Where required, use special Betamotor tools. Use Betamotor spare parts only. For their codes refer to the spare parts manual for the specific vehicle or version. The warranty and liability on vehicle safety lapses when maintenance or repairs: · Are NOT performed by workshops specialised in repairing mopeds and motorcycles; · Are NOT carried out carefully following the requirements contained in the technical documentation; · Are NOT carried out using special Betamotor tools, where required; · Are NOT carried out using Betamotor official spare parts. Carefully read this manual in its entirety before working on the engine. Good knowledge of all components making up the engine and all the procedures to be followed for inspection and maintenance help extend the life of the engine. The paragraphs feature schematic illustrations highlighting each topic in order to make the text immediately understandable. Informative note Betamotor S.p.A. is committed to a policy of ongoing improvement of its products. This is why you might notice slight differences between the content of this document and the vehicle on which you are about to carry out repairs and/or maintenance. Betamotor S.p.A. models are exported to a number of countries where there are different rules concerning the Highway Code and vehicle type-approval procedures. Betamotor S.p.A. therefore reserves the right to modify its products and technical documentation at any time without prior notice, thank you for your understanding. We respect and defend the environment Everything we do has an impact on the whole Planet and its Resources. To safeguard the interests of the entire Community, Betamotor S.p.A. would like to raise the awareness of customers and technical service operators on ways of using the vehicle and disposing of its parts entirely in compliance with applicable regulations in terms of environmental pollution, waste disposal and recycling. SAFETY Carbon monoxide · Exhaust gases contain carbon monoxide, which is poisonous. Carbon monoxide may cause loss of consciousness and lead to death. If the engine needs to be started, make sure the location is well-ventilated. Never start the engine indoors. · The engine can be started indoors only if fitted with the appropriate exhaust gas extraction devices. Petrol · Petrol is extremely flammable and can be ex- plosive under certain conditions. · Keep sources of heat, sparks and flames away from the work area. · Always work in a well-ventilated area. · Never use petrol as a solvent for cleaning. Do not handle it unless strictly necessary. · Never use petrol to clean components by means of compressed air. · Keep out of the reach of children. Engine oil · Motor oil can cause skin conditions if it remains in contact with the skin often and for prolonged periods. · In case of contact with engine oil, wash with soap and water as soon as possible. · In case of contact with the eyes, rinse them with plenty of water and seek medical advice. · If swallowed, do not induce vomiting in order to prevent the product from entering into the lungs; seek immediate medical advice. If you believe the product has entered the lungs, take the person concerned to hospital immediately. · Waste oil contains dangerous substances that are harmful for the environment. In order to change it one must be equipped for disposal, in compliance with applicable laws. · Do not discard waste oil into the environment. · Keep out of the reach of children. 2 INTRODUCTION www.betamotor.com Coolant liquid · In some situations, the ethylene glycol con- tained in the coolant is flammable and its flame is invisible. Should ethylene glycol catch fire, it can cause burns even though its flame is invisible. · Do not bring the coolant into contact with hot parts. These parts could be hot enough to cause the liquid to ignite. · The coolant (ethylene glycol) may irritate the skin and is poisonous if swallowed. · Should the coolant come into contact with the skin, immediately remove contaminated clothing or footwear and wash with soap and water. In the event of contact with the eyes, rinse with plenty of clean water and seek medical advice immediately. Should it be swallowed, do not induce vomiting in order to prevent the product from entering the lungs. Administer clean water, immediately take the person concerned to hospital, and show this product to hospital staff. · In the event of exposure to a high concentra- tion of vapours, move the person concerned to an uncontaminated area and seek medical advice if necessary. · Do not remove the radiator cap when the en- gine is still hot. Since the coolant is pressurised, it may spurt out violently and cause burns. · The coolant contains dangerous substances that are harmful for the environment. In order to change it one must be equipped for disposal in compliance with applicable laws. · Do not disperse coolant into the environment. · Keep out of the reach of children. Hot parts · The engine and the exhaust system get very hot and remain at that temperature for a long time, even after the engine has been turned off. Wait for them to cool down before handling these parts or carrying out work on areas around them. Wear insulated gloves. WARNINGS The information contained in this paragraph is important to ensure the operations carried out on the engine are performed without causing damage. · Before disassembly, thoroughly clean the mo- torcycle. · While disassembling it, clean all the parts and place them in containers accurately following the order of disassembly. · Always use special tools wherever necessary and when required. · Always use glues, sealant and lubricants wherever required. Follow the indications concerning their technical features. · Always replace parts such as gaskets, O-rings and safety washers with newly supplied parts. · When loosening or tightening nuts or screws, always start with the larger ones or from the centre. Always adhere to the specified tightening torques. · Use only Betamotor original spare parts. 3 ENGINE ENGINE TECHNICAL SPECIFICATIONS CHARACTERISTIC DATA Bore [mm]/Stroke [mm] Displacement [cm³] Compression ratio Primary 1st gear ratio 2nd gear ratio 3rd gear ratio 4th gear ratio 5th gear ratio 6th gear ratio ENGINE RR250 RR300 66.4/72 72/72 249 293 13.2:1 11.9:1 TRANSMISSION RR250 RR300 27/72 27/72 12/31 12/31 15/28 15/28 19/28 19/28 20/24 20/24 27/27 27/27 28/24 28/24 www.betamotor.com 4 www.betamotor.com SPECIAL EQUIPMENT ENGINE 1. Complete EVO 2T crankcase uncoupler 007.14.010.80.00 2. Special wrench 029.14.002.50.00 3. Squish measuring tool 026.14.010.00.00 4. Front bracket for fastening engine to stand 026.14.003.00.00 5. Flywheel blocking tool 026.14.005.50.00 6. Flywheel extractor 36.25173.000 7. EXC engine universal assembly equipment 36.25132.000 8. Special wrench 026.44.029.00.00 9. Special wrench 026.44.028.00.00 10. Special wrench 007.44.035.00.00 11. Special wrench 026.14.012.50.00. Symbols 6Nm Value Tightening torque Threadlocker medium-resistance High-resistance threadlocker Silicone paste Grease 5 1 1 ENGINE REMOVAL FROM VEHICLE · Carefully wash the vehicle; · Remove the engine guard plate; · Place the vehicle on an adequate stand. ENGINE REMOVAL FROM VEHICLE 2 6 To dismantle the tank from the vehicle it is necessary to remove the seat, disconnect the tank ventilation pipe, position the fuel valve on OFF and disconnect the fuel pipe from the valve. AT T E N T I O N ! Perform the operation with the engine cold and in a well-ventilated area. AT T E N T I O N ! Fire hazard! Fuel is easily flammable. Do not carry out the operation near open flames or lit cigarettes and always turn off the engine. Wipe off any traces of spilled fuel immediately. Remove the screw 1 fastening the tank to the frame, and the screws 2 (one per side) fastening the side panel to the radiator. 1 Lift the tank slightly and: · remove pipe 3 1 3 ENGINE REMOVAL FROM VEHICLE · disconnect the connector 4 4 Lift the tank from the back and remove it backwards. 7 ENGINE REMOVAL FROM VEHICLE 1 6 · Remove the frame guards 5 (one on each 5 side) and the pinion guard 6. 7 8 · Remove the circlip 7 and extract the pinion. Rest the chain against the upper wedge 8. · Remove the screw 9. 9 · Remove the screws 10. · Remove the silencer from the vehicle. · Remove the exhaust pipe. 10 8 11 12 ENGINE REMOVAL FROM VEHICLE · Remove the screws 11 fastening the clutch actuator to the crankcase half. 1 AT T E N T I O N ! Do not operate the clutch lever with the actuator uncoupled from the engine. · Drain the cooling system through the screw 12 and let the liquid outflow into a container (the cooling circuit contains 1.3l of liquid). Remove the radiator cap. Note: To make the circuit easier to empty, it is advisable to slightly tilt the vehicle on the left side. · Remove the protection grids from the radia- tors. · Disconnect the water hoses from the engine and from the left radiator. 9 ENGINE REMOVAL FROM VEHICLE 1 · Remove the fixing screws and remove the left radiator. · Disconnect the water hoses from the engine and from the right radiator. 10 · Remove the fixing screws and remove the right radiator. 1 ENGINE REMOVAL FROM VEHICLE · Disconnect the spark plug cap. · Cut all straps binding the engine's electric system to the clutch pipe and to the frame. 15 13 14 · Release the connectors 13, 14, 15 of the en- gine ignition unit and disconnect them from the electrical system. 11 1 · Remove the starter motor cable fixing nut. ENGINE REMOVAL FROM VEHICLE · Remove the head connections and spark plug. Note: It is advisable to insert a clean cloth into the spark plug housing in order to prevent accidental introduction of dirt into the cylinder. · Release and remove the brake pedal return spring 16. Remove the kickstarter lever (optional). · Remove the gear lever. 16 · Pull out the mixer tube 17 from the intake 18 manifold and tube hole 18. 17 12 AT T E N T I O N ! When the mixer tube has been disconnected, plug it to prevent emptying. 1 ENGINE REMOVAL FROM VEHICLE · Loosen the carburettor straps from the air fil- ter sleeve and from the manifold. · Disconnect the connector 19. 19 13 ENGINE REMOVAL FROM VEHICLE 1 21 20 · Remove the subframe lower fixing screws 20 (one on each side) and loosen the upper screws 21 (one on each side). · Rotate the entire filter box unit. · Remove the carburettor, leaving it connected to the gas cable. · Cut the clamp shown. 14 ENGINE REMOVAL FROM VEHICLE · Disconnect the connector 22. 1 22 · Remove the brake light wiring A and starter motor cable B from the carburettor. A B 15 ENGINE REMOVAL FROM VEHICLE 1 · Remove the shock-absorber pin 23. 23 · Remove the swingarm pin. Pull the entire wheel/swingarm unit outwards. 25 16 · Remove the gear lever 24 and the engine pins 25. 24 · Extract the engine from the frame and apply it to the specific stand, code 3625132 000, using the specific front fixing bracket, code 026140030 000. 2 ENGINE DISASSEMBLY 2 Secure the engine to the specific support stand code 3625132000 by means of the front fixing code 026140030 000, in order to work in comfort and safety. Then proceed as follows. ENGINE DISASSEMBLY 2.1 CLUTCH/GEAR OIL DRAIN Remove screw 1 and let the oil drain. 1 2.2 REMOVAL OF CLUTCH 2 CONTROL ROD AND PIN- ION SPACER 1 Pull out the spacer 1. Pull out the clutch control rod 2. 17 ENGINE DISASSEMBLY 2 2.3 REMOVAL OF PISTON, CYL- 1 INDER AND HEAD Remove the spigot screws 1 together with the copper washers. Remove the head and the two O-rings. Remove the four screws 2. 2 Remove the three screws 3 and cover 4. 3 4 18 Release the lock 5 and remove it. 5 2 ENGINE DISASSEMBLY Release the control rod 6. 7 A Remove the gasket 7. It may be necessary to slightly force the rubber gasket 8; place a metal pin A between the lever and the gasket 8 and slightly force it outwards. 6 8 Removal of gasket 7. 19 2 Remove the four collar nuts 9. ENGINE DISASSEMBLY 9 Extract the cylinder and base gaskets. A 10 Removal of piston circlip. AT T E N T I O N ! Place a clean cloth between the piston and the crankcase to keep foreign objects or simple solid residues from falling inside the base. Remove the circlip 10 by gripping it with a pair of fine nose pliers A. Remove the pin bolt using a universal extractor for pin bolts. Remove the piston, the pin bolt and the bearing from the connecting rod foot. Removal of pin bolt. 20 1 2.4 2 REMOVAL OF IGNITION UNIT The ignition unit is made up of the flywheel (or rotor), the pick-up unit and the stator, which is one with the flywheel cover. ENGINE DISASSEMBLY 2 Fixing screws 1 of flywheel cover 2. 3 2.4.1 REMOVAL OF FLYWHEEL COVER Remove the five screws 1 fastening the flywheel cover 2 to the left crankcase. Remove the flywheel cover and the gasket placed between the crankcase and the cover. Pay attention to the two centring pins 3 on the crankcase. The two designated reference pins 3 for the flywheel cover. 5 3 4 2.4.2 Stator removal Remove the two screws 1 fixing the stator 2 to the flywheel cover 3. Extract the plate 4 and the cable gland 5 from the cover and take out the stator. 1 2 Disassembly of stator from cover. 21 ENGINE DISASSEMBLY 2 A Removal of flywheel nut. 2.4.3 REMOVAL OF FLYWHEEL Block the flywheel using the special tool A (cod. 026140040 000) and remove the fastening nut securing the flywheel to the crankshaft. Note: Once the nut has been unscrewed, pay attention to the special elastic washer placed between the nut and the flywheel. To remove the flywheel, tighten the extractor B (code 3625173) onto the threaded part on the flywheel. Keep the extractor blocked with a spanner and tighten the screw on the extractor using a box spanner. B Release of flywheel using special tool B. 2 2.4.4 REMOVAL OF PICK-UP UNIT Remove pick-up unit 1 by loosening the two fixing screws 2. 1 Removal of pick-up unit. 22 ENGINE DISASSEMBLY EXPLODED VIEW OF ELECTRIC KICKSTARTER: 1) Start motor; 2) O-ring; 3) Screws; 4) Bendix coupling; 5) Bush with collar. 2.5 2 REMOVAL OF ELECTRIC IG- NITION The electric ignition is carried out by means of start motor 1 that meshes on the Bendix coupling 4. The coupling gear axially shifts and meshes onto the ring gear, which is one with the flywheel, due to the start motor rotation. The coupling gear retracts to its rest position, once the motor action ends. 23 2 2.5.1 REMOVAL OF START MOTOR Remove the two screws 1 and extract the motor. ENGINE DISASSEMBLY 1 Removal of start motor. 1 Removal of Bendix coupling. 2.5.2 REMOVAL OF BENDIX COUPLING Extract the Bendix coupling 1 once the complete flywheel cover and flywheel have been removed (see par. 2.4.1). 24 ENGINE DISASSEMBLY 2.6 2 REMOVAL OF COOLANT LIQUID PUMP, CLUTCH UNIT, MAIN GEAR, CEN- TRIFUGAL UNIT, GEAR- SHIFT ORGANS, KICK- START Remove the cover 1 by loosening the screws 2 to access the coolant liquid pump. Note: remove the coolant liquid pump impeller if having to intervene on the centrifugal unit. 1 Coolant liquid pump cover screws. 2 25 ENGINE DISASSEMBLY 2 In order to only access the clutch unit, the outer clutch cover 3 must be removed by loosening the screws 4. 3 4 Outer clutch cover screws. 26 ENGINE DISASSEMBLY When doing a complete overhaul of the engine or of gearshift organs, kickstart, primary transmission or centrifugal unit, the inner clutch cover 5 must be removed by loosening the nine screws 6. 2 5 Inner clutch cover screws. A 6 Pay attention to the two reference pins A placed between the right crankcase half and the inner clutch cover while disassembling. Two centring pins A for inner clutch cover coupling. 27 2 1 2.6.1 REMOVAL OF COOLANT LIQUID PUMP Loosen fixing screw 1 once the coolant liquid pump cover has been removed. ENGINE DISASSEMBLY Cooling pump fixing screw. 2 3 Extract the impeller 2 and the thrust washer 3. Removal of impeller. 5 4 Removal of pump body and gasket. Extract the complete pump body 4 and remove gasket 5. 28 2.6.2 REMOVAL OF CENTRIFUGAL UNIT AND LEVERAGE 2 Access the centrifugal unit and linkage by removing 1 the inner clutch cover. Disassemble the adjustment cover 1 by removing the two screws 2, once the pump impeller has been removed (par. 2.6.1). 2 ENGINE DISASSEMBLY Removal of centrifugal adjustment cover. 4 3 5 8 Remove the unit consisting of adjusting springs 3, auxiliary springs 4 and the spring guide 5. After removing the screw fixing the rocker arm 6 to the centrifugal control lever 7, extract the rocker arm with control rod and gasket 8. 6 7 Disassembly of control rod-rocker arm unit. 29 2 9 9 Extract the centrifugal control lever 7 together with the two thrust washers 9. ENGINE DISASSEMBLY 7 Removal of centrifugal control lever. 10 Extract the complete centrifugal unit 10. Extraction of centrifugal unit. 30 1 2 6 8 3 1) Adjustment cover; 2) Adjustment spring; 3) Auxiliary spring (if any); 4) Spring guide; 5) Rocker arm; 6) Centrifugal control lever; 7) Thrust washers; 8) Screw; 9) Centrifugal unit. 5 4 9 7 ENGINE DISASSEMBLY 2 31 ENGINE DISASSEMBLY 2 3 1 2 A 2.6.3 DISASSEMBLY OF CLUTCH UNIT AND COUNTERSHAFT COUNTERWEIGHT Keep the clutch unit blocked by using the special tool A (code 029.14.002.50.00) remove the screws 1 which fasten the clutch cap 2 to the clutch drum. Remove the clutch cap together with the washers and relevant springs. Extract the complete pressure plate unit 3 and the clutch disc pack 4. 7 32 4 In order to complete disassembly of the clutch unit, open the safety washer 5 by using a chisel and remove the nut 6. WARNING! Do not remove the sliding pins 7. 6 5 A To unscrew the nut 6, the clutch drum must be blocked with the appropriate tool A (code 029.14.002.50.00). Then remove the nut and relevant safety washer. WARNING! Do not use the pneumatic gun. ENGINE DISASSEMBLY Using the special primary tool A (code 029.14.002.50.00), disassemble the nut that tightens the primary gear 8 onto the crankshaft. 2 WARNING! The nut must be turned clockwise. 8 A 8 12 11 10 7 9 Extract the clutch drum 8, the washer 9, the case 10, the roller cage 11 and the centre bearing 12. It is possible to remove the sliding pins 7. Keep the counterweight locked in place 13 using the 13 special tool B (code 026.14.012.50.00) and loosen the screw. B 33 ENGINE DISASSEMBLY 2 Extract the primary gear 14. Removal can be facilitated by using a universal extractor. 14 Using the extractor, remove the counterweight 13. Note: it is advisable to keep the locking screw 14 in 14 place, using it as a support for the extractor. 13 34 1 2 4 3 The pedal kickstart. 3 2.6.4 PEDAL KICKSTART - OPTIONAL 2 The pedal kickstarter consists of the pedal which, attached to the kickstarter shaft 1, moves the kickstarter gear 2. This gear moves the idler wheel 3, which engages in its turn with the clutch case. The device recoils thanks to the spring 4. ENGINE DISASSEMBLY Remove the external circlip 5 and extract the external thrust washer 6, the idler gear 3, the internal thrust washer 7 and the second circlip 8. The circlips and thrust washers are interchangeable. 5 Removal of circlip 5 of idler gear 3. 5 8 6 7 Two circlips 5 and 8 and thrust washers 6 and 7. 35 2 A 4 Using a pair of pliers, pull the end A of the spring 4 out of the housing hole on the crankcase and move it to a resting position by turning it anti-clockwise. ENGINE DISASSEMBLY Releasing spring from crankcase. Turn the shaft anti-clockwise and pull it off together with the sleeve 9, the spring 10 and the thrust washer 11. Extraction of shaft from crankcase. 2 9 1 11 4 10 Complete pedal kickstart shaft. 36 ENGINE DISASSEMBLY 3 1 1 2.6.5 EXTERNAL UNIT 2 GEARSHIFT The external gearshift consists of the drive shaft 1 on which the movable and fixed pawls are applied. The fixed pawl is the guide of the movable pawl, which has the task of engaging the stop cam 2. In its turn, this is fastened to the internal gearshift and is kept in the fixed position by the cam stop lever. 2 In order to disassemble the drive shaft, just keep the movable pawl return spring 3 pressed and extract the shaft together with the specific washer 4. 4 Gearshift with washer. 2 5 In order to disassemble the stop cam 2, keep the cam stop lever moved 5, loosen the screw 6 and pull out the stop cam 2. 6 Disassembly of gear stop cam. 8 In order to disassemble the stop lever, loosen 9 the screw 7 enough to allow the lever to move axially and overcome the cylinder segment A of the desmodromic device. Move the return spring 8 to the resting position and remove the screw, the washer 9, the spring together with the spacer, the internal washer (not shown in the image) and finally the cam stop lever. 7 A Disassembly of cam stop lever. 37 2 2.7 INTAKE SYSTEM The intake system mainly consists of the intake manifold 1 and reed valve 2 and the spacer 3. ENGINE DISASSEMBLY 3 1) Intake manifold; 2) Complete reed valve; 3) Gasket. 4 1 2 Disassemble by removing the screws 4 fastening the intake manifold and the reed valve to the crankcases. Fixing screws. 38 2.8 2 C R A N KS H A F T, GEAR- BOX UNIT AND INTERNAL GEARSHIFT To access the crankshaft, gearbox unit and internal gearshift, the left and right crankcases must be detached. Below are the required instructions. ENGINE DISASSEMBLY A 1 2.8.1 OPENING THE CRANKCASE A Remove the thirteen screws 1 fastening the crankcases. ATTENTION! Loosen the two equipment fixing screws A. Removal of crankcase screws. C B Apply special tool B to the right crankcase half following the punching on the tool itself. Fix the tool with the four M6x20 screws (maximum torque 10Nm). Tighten screw C on the special tool. Slightly hit the gear secondary with a rubber mallet during said operation. Once the crankcases have been detached, remove the two fixing screws to the equipment A and remove the left crankcase. Crankcase uncoupling stage. 3 Remove the two rear 2 and front 3 reference pins. Remove the coupling gasket to the two crankcases. 2 Crankcase half reference pins. 39 2 2.8.2 COUNTERWEIGHT PORT SHAFT SUP- Once the crankcase halves have been uncoupled, push the counterweight support shaft inwards 1. 1 ENGINE DISASSEMBLY 2.8.3 CRANKSHAFT 1 The crankshaft 1 can be pulled out manually. Gently hit the right end of the crankshaft in case of resistance. Removal of crankshaft. 40 2 4 1 Removal of fork support pins 1. 2 ENGINE DISASSEMBLY 3 4 2.8.4 INTERNAL GEARSHIFT UNIT AND COMPLETE GEARBOX 2 The internal gearshift unit is made up of the desmodromic device 1 on which the fork 2 and two forks 3 are engaged. The forks, supported by the pins 4, drive the sliding wheels of the gearbox, allowing the desired ratio to be engaged. The desmodromic device is controlled by the stop cam located in the external gearshift unit. Manually extract the two pins 4 so that the forks can be released and removed. Turn the fork 2 which drives the sliding gear on the primary unit clockwise to release it from the desmodromic control. 3 Carry out the same steps, though in the opposite direction, on the forks 3 driving the sliding gears on the secondary shaft. Extract the desmodromic device. Disengaging the drive forks from the desmodromic device. Extract the forks together with the guide bushes 5. 5 Extraction of forks from gearbox unit. 41 26 Extract the whole gearbox unit consisting of primary 7 6 and secondary 7 unit. ENGINE DISASSEMBLY Extraction of complete gearbox unit: 6 primary unit, 7 secondary unit. 8 Note: Make sure you have removed circlip 8 on the clutch side gearbox secondary. 42 ENGINE DISASSEMBLY 2.9 2 DISASSEMBLY OF PARTS FROM CRANKCASES Once the crankcases have been detached, it may be required to remove the various components attached to them. The bearings must be replaced if there is any play or jamming during rotation. For removal, heat the crankcase halves for 20 minutes at about 150°C. Place the crankcase halves on a large surface where their whole seal surface can rest. Remove the bearings by following the indications below. 2.9.1 RIGHT CRANKCASE HALF On the external side, remove the kickstart ramp 1 (optional), the crankshaft spacer 2 and relative O-ring and crankshaft oil seal 3. 1 3 2 Kickstart ramp 1), crankshaft spacer 2) (and relative O-ring), oil seal 3). 43 2 Remove the desmodromic control bearing seal screw 4 on the inside. ENGINE DISASSEMBLY 4 Bearing safety screw. 6 5 10 9 11 The bearings 5, 6, 7, 8 and 9 are removed from the outside inwards. To disassemble bearing 9 remove the fixing screw 7 10. 8 The bearing 11 is removed from the outside using a universal extractor, after removing the fixing plate 12. 12 The centrifugal shaft bearing can be removed by using a universal extractor that must rest onto a purposely created metal plate. 44 ENGINE DISASSEMBLY 2.9.2 LEFT CRANKCASE HALF Remove the crankshaft oil seal 1, the secondary shaft oil seal 2 and the gearshift shaft oil seal 3 on the external side. 2 2 1 3 Removal of outer side left crankcase half oil seal. 4 5 8 6 The bearings 4, 5, 6, 7 e 8 are removed from the outside inwards. 7 Removal of left crankcase half bearings. 45 ENGINE CHECKS AND ASSEMBLY 3 3 ENGINE CHECKS AND ASSEMBLY Before reassembling the engine, a series of crucial checks must be carried out to ensure the engine is in good working order. In order to insert the bearings into the crankcase halves, heat the crankcase halves to 150°C and keep them at constant temperature for 20 minutes. Place said crankcase halves on a large surface where their whole seal surface can rest. When the bearings cool down, they drop into their seats on their own. 3.1 CRANKCASE HALF The crankcase halves have some parts that require care, and their integrity and condition must be checked. The checks and assembly operations of the individual parts coupled to the crankcases are described below. The threading and oil passages A should be cleaned thoroughly by using a degreaser A and compressed air. Crankshaft bearings lubrication holes. 46 1 2 3 3.1.1 APPLICATION OF RIGHT CRANKCASE HALF PARTS 3 Apply the bearings 1, 2, 3 and 4 until flush. Block bearing 4 with the specific screw by depositing the threadlockers. Tighten to the specified torque. ENGINE CHECKS AND ASSEMBLY 6Nm 4 Positioning of the right crankcase half bearings. 7 85 Apply the bearing 5 from the crankcase half external side, until it is flush, and bearing 6 as shown in the drawing. Apply new oil seals, to be pressed all the way until fully seated. Apply the bearing 7 until flush. Apply the plate 8 and fasten it with a screw after applying medium strength threadlocker. Tighten to the specified torque. 6 Application of bearings from the right crankcase half external side. Position of right crankcase half gearshift shaft bearing. 47 ENGINE CHECKS AND ASSEMBLY 3 10Nm 9 10 Application of kickstart ramp. EXPLODED VIEW OF GEAR STOPPING DEVICE: 18) Lever; 16) Spring; 17) Spacer; 19) 6x20x1 washer; 20) Screw M6x20 10Nm If present (optional), apply the kickstart ramp 9 and fasten the screws 10 at 10Nm, by depositing a medium strength threadlocker. Apply the gear stopping device as follows. Keeping the tightener on lever 18 facing towards the crankcase half, apply the spacer 17 onto it, inserting the smaller diameter segment in the lever. Apply the spring 16 so that the hook fits into the groove on the lever 18 and then apply the washers 19 and the M6x20 screw 20, after spreading medium strength threadlocker on the thread. Apply the entire device on the crankcase half so that the straight segment of the spring rests on the bearing seat. Tighten the screw to the indicated torque. C Application of cam stop lever. 48 2 41 3 3.1.2 APPLICATION OF LEFT CRANKCASE HALF PARTS 3 Apply the bearings 1, 2, 3 e 4 from the crankcase half internal side, until flush. ENGINE CHECKS AND ASSEMBLY Application of left crankcase half bearings. 5 6 Application of left crankcase half parts. Apply the bearing 5 from the crankcase half external side, as shown in the drawing. Apply the crankshaft oil seal, gear secondary shaft and gearshift shaft. Apply the bush with collar 6. Apply new oil seals, to be pressed all the way until fully seated. Apply new oil seals, to be pressed all the way until fully seated. Position of left crankcase half gearshift shaft bearing. 49 ENGINE CHECKS AND ASSEMBLY 3 Deflection/Off-centring of crankshaft. 3.2 CONNECTING ROD AND ENGINE SHAFT CHECK After having checked the state of wear of the coupling surfaces, check the offset of the half shaft axes (by measuring the radial oscillation) by placing the crankshaft in between two tailstocks or similar instrument. Verify the maximum measurement variation during a complete turn, using comparators positioned on the coupling surfaces with the crankshaft bearings. Allowed limit value: 0.02mm Check the axial play between the connecting rod head and the half shafts. Recommended play: 0.39÷0.72mm Connecting rod axial play. The distance between the two shoulders must be: 62±0.05 50 Half-shoulder 1 If replacing the inserts, apply the screws with high-resistance threadlocker and tighten at the specified torque. 3 ENGINE CHECKS AND ASSEMBLY 5Nm 3.3 ASSEMBLY OF COMPLETE CRANKSHAFT When all the aforementioned checks have been carried out and the worn parts replaced, grease the crankshaft oil seal on the right crankcase half and couple the crankshaft to the left crankcase half. Keep the conical part A on the crankshaft facing you. In order to carry out this operation, you must just push the shaft axially towards the crankcase. Apply the two centring bushes 1 and 2. 2 A Insertion of the crankshaft in the right crankcase half. 51 ENGINE CHECKS AND ASSEMBLY 3 Check of wear of forks and gearwheels. 3.4 GEAR UNIT: CHECKS AND R E A S S E M B LY The gearbox unit is made up of the gearshift and of the gearbox itself. The gearshift in its turn is divided into external and internal gearshift. The checks and procedures for inspecting and reassembling these units to the engine are set out below. 3.4.1 GEARBOX UNIT CHECK Use protective jaws to clamp the main shaft and secondary shaft. Use a thickness gauge to check the axial play between the gearshift forks and the gearwheels. The measured play must not exceed the service limit indicated below: service limit: 0.5mm If the measured axial play is greater, before replacing either the gearwheels or the forks, check the state of wear of the latter (par. 3.4.4) Remove the various elements and check that: · the support surfaces of the main shaft and sec- ondary shaft show no abnormal wear or signs of seizure; · the sides of the teeth are free from chipping or abnormal wear; · the sliding areas of the gearwheels show no ab- normal wear or traces of seizure; · the front claw clutches of the gearwheels are not chipped or rounded; · the roller bearings are intact and efficient; · none of the thrust washers show traces of ab- normal wear or meshing. Should any of these defects be found, replace the concerned parts. 52 3.4.2 PRIMARY UNIT ASSEMBLY Before proceeding with reassembly, clean all the parts thoroughly and oil with gear oil. Always replace the circlips. Clamp the main shaft 1 (using protective jaws), so that the grooved end faces downwards. 3 ENGINE CHECKS AND ASSEMBLY EXPLODED VIEW OF PRIMARY UNIT: 1) Main shaft; 2) Roller cage 22x26x13; 3) Fifth on primary; 4) Thrust washer; 5) Circlip sw15; 6) Third and fourth on primary; 7) Thrust washer; 8) Sixth on primary; 9) Second on primary; 10) Thrust washer 17x30x1 Insert onto the lower cylinder part of the shaft: the roller cage 2, the 5th gear 3 turning the front claw clutches upwards, the thrust washer 4 (26x32x1.5) and the circlip 5. Insert the 3rd 4th sliding gear 6 so that the smaller gear faces downwards, and then insert circlip 5. Insert the thrust washer 7 (23x32x1.5), the roller cage 2, the 6th gear 8 with the front claw clutch facing downwards, the 2nd gear 9 with the cavity facing upwards and finally the thrust washer 10 (17x30x1). 53 3 3.4.3 SECONDARY UNIT ASSEMB LY Before proceeding with reassembly, clean all the parts thoroughly and oil them by using gear oil. Always replace the circlips. Clamp the secondary shaft 20 (using protective jaws), so that the grooved end faces downwards. ENGINE CHECKS AND ASSEMBLY EXPLODED VIEW OF SECONDARY UNIT: 4) Thrust washer; 5) Circlip sw15; 7) Thrust washer; 10) 17x30x1 thrust washer; 11) First on secondary; 12) 20x24x10 roller cage; 13) 20x30x1 thrust washer; 14) Fifth on secondary; 15) Roller cage; 16) Third on secondary; 17) Fourth on secondary; 18) Sixth on secondary; 19) Second on secondary; 20) Secondary shaft 54 Insert onto the lower cylinder part: the roller cage 15, the 2nd gear 19 so that the front claw clutches face downwards, the thrust washer 4 (26x32x1.5) and the circlip 5. Insert the 6th gear 18 so that the fork seat faces upwards and circlip 5. Insert the thrust washer 7 (23x32x1.5), the two roller cages 15, the 4th gear (17) with the front claw clutches facing upwards, the 3rd gear (16) with the front claw clutches facing downwards, the thrust washer 7 (23x32x1.5) and the circlip 5. Insert the 5th gear (14) with the fork seat facing downwards, the thrust washer 13 (20x30x1), the roller cage 12, the 1st gear (11) with the front claw clutches facing upwards and finally the thrust washer 10 (17x30x1). ENGINE CHECKS AND ASSEMBLY 3.4.4 CHECKING THE FORKS, FORK PINS AND DESMODROMIC DEVICE 3 The internal gearshift is made up of: · two forks 13 which drive two gears on the sec- ondary unit; · one fork 14 which drives one gear on the primary unit; · three guide pin bushes 15; · two fork pins 16; · desmodromic gearshift 18 whose rotation drives the forks thus selecting the desired gear. EXPLODED VIEW OF INTERNAL GEARBOX CONTROL UNIT: 13) 1st - 4th fork; 14) 5th-6th fork; 15) bush; 16) fork pin; 18) desmodromic control Check to make sure that the guide pins that support the bushes 15 have no traces of meshing or abnormal wear and that the bushes are not worn. 55 ENGINE CHECKS AND ASSEMBLY 3 A ID Guide pin Make sure the distance A between the outer faces of the fork is not less than the minimum indicated below: Minimum acceptable distance: 4.25mm Check to make sure that the inside diameter D of the fork pin seats is below the limit: Fork inside diameter limit: 13.83mm Make sure that the fork pins on which they slide have an outside diameter above the limit (to be measured in the sliding areas of the forks and in the housing areas with the crankcases): Fork pin outside diameter limit: 13.75mm Make sure that the desmodromic control device has no corroded or worn areas especially in the grooves in which the guide pins of the forks are engaged. Check the bearing on the desmodromic device. Replace it in the event of signs of meshing or jams during motion. 56 ENGINE CHECKS AND ASSEMBLY 2 3 1 4 Insertion of the gearbox in the left crankcase half. 3.4.5 GEARBOX AND INTERNAL GEARSHIFT ASSEMBLY 3 Insert the entire primary 1 and secondary unit 2 into the respective seats on the left crankcase half simultaneously. Remember to oil the gears with plenty of gear oil and to grease the shafts supporting them with graphite grease in the mating areas with the bearing. Make sure that all the parts slide properly. Insert the centre bearing 3 and the O-ring 4 on the secondary unit. 3 4 Detail of centre bearing 3 and O-ring 4 coupled to the secondary shaft. 57 ENGINE CHECKS AND ASSEMBLY 35 6 Introduce the forks together with the guide bush- 6 es on the gear tracks. Namely: the smaller fork 5 drives the sliding gear on the primary unit, while the other two (6) drive the sliding gears on the secondary unit. Note: the two forks 6 are interchangeable and their positioning is univocal, since the drive pin must face the desmodromic device. Place the forks in their original positions if none of the components are replaced. Application of forks to gearwheels. 7 Insert the desmodromic device in the specific bearing. In order to do this, the cam stop lever 7 must be rotated towards the top part of the engine. Insertion of desmodromic device in the specific bearing. Note the rotation of the gear stop lever. Position the fork 5 of the primary unit in the cen- tral guide of the desmodromic device 8, insert the fork pin inside the fork and insert the pin in its 5 8 specific seat in the crankcase half. Place fork 5 of the primary unit in the central guide of desmodromic device 8. 58 ENGINE CHECKS AND ASSEMBLY 8 6 Position the two forks 6 of the secondary unit in the external guides of the desmodromic device 8 and, just like the primary unit fork, insert the fork pin first in the pins and then in its proper seat. Remember to oil the shafts, forks and the desmodromic device with plenty of gear oil. 3 6 Positioning of the secondary unit forks 6. In the external guides of desmodromic device 8. Apply some grease on the crankcase edge in the mating area with the gasket and place a new gasket. View inside the right crankcase with crankshaft, gearbox shafts complete with wheels, internal gearshift and gasket. 59 3 Apply circlip 9 on the clutch side gearbox sec- 9 ondary. ENGINE CHECKS AND ASSEMBLY 3.4.6 COUNTERWEIGHT PORT SHAFT SUP- Check that the areas where the shaft rests on the bearings are intact and free of any traces of meshing or abnormal wear. Otherwise replace the shaft. Insert the shaft all the way as shown in the figure. 60 ENGINE CHECKS AND ASSEMBLY 3.5 CLOSING THE CRANKCASE 3 ENGINE Apply a thin layer of grease on all oil seals. Heat up the engine shaft bearing on the left crankcase half, being careful not to burn the oil seal. Press the left crankcase half towards the right, making sure that the shafts and pins on the crankcases fit into the respective housings and that the crankcase half is not offset. By heating the bearing it will be possible to manually move close to the right crankcase half. Put the clamping screws in place based on length, as pictured. The table below contains indications for applying these screws. Tighten according to a cross sequence. Positioning of crankcase coupling screws. Screw number 8 9 Screw size Threading diameter Threading length M6 40 M6 50 Threadlocker application NO NO Tightening torque [Nm] 10 10 Cut the extra piece of gasket between the two crankcase halves in the area of the cylinder and reed valve seat. 61 ENGINE CHECKS AND ASSEMBLY 3 0.35÷0.50 3.6 EXTERNAL GEARSHIFT Before reassembling the external gearshift, check its state of use. While for the stop cam it is enough to make sure it is free from abnormal wear or meshing, the gearshift drive shaft needs more indepth inspections. 3.6.1 CHECKING THE COMPLETE DRIVE SHAFT With the complete device, make sure that the distance between the movable pawl and the drive shaft is between 0.35÷0.80mm. Should the distance be greater, replace the movable pawl. Allowed distance between shaft and pawl. 2 1 4 In order to replace the movable pawl 1, disassemble the return spring of the gearshift 2, the spring guide 3, the spring 4 (which must be compressed and pulled out of its seat) and the pawl, moving it completely towards the shaft 5. 3 5 Complete drive shaft: 1) Movable pawl; 2) Gearshift return spring; 3) Spring guide; 4) Spring; 5) Gearshift drive shaft. 62 3 ENGINE CHECKS AND ASSEMBLY Exploded view of gearshift. 5) 14x30x1 thrust washer; 6) Gearshift return spring; 7) Spring guide; 8) Pawl return spring; 9) Movable pawl; 10) Gearshift shaft. For reassembly, couple the movable pawl 9 to the drive shaft 10 and, while compressing it, insert the spring 8 between the movable pawl and the drive shaft. Then apply the spring guide 7, the gearshift return spring 6 and finally the thrust washer 5 (14x30x1). The gearshift return spring must be positioned as in the figure to be able to carry out its function. Gearshift drive shaft: note the gearshift return spring position. 63 ENGINE CHECKS AND ASSEMBLY 3 2 10Nm 4 3.6.2 EXTERNAL GEARSHIFT ASS E M B LY Rotate the gear stop lever 1 clockwise so that the spring is compressed. To keep the lever in this position, an aluminium rod A can be inserted into 1 the small hole, as shown in the figure. C A 3 Apply the gear stop cam 2 to the protruding end of the desmodromic control. The stop cam has only one correct position, which is determined by the specific shape of the end of the desmodromic device and of the bottom part of the stop cam. Next, fit the M6x30 tightening screw 3 between the stop cam and the desmodromic control, after applying medium-resistance threadlocker: tighten at the indicated torque. Remove the rod A. Insert the drive shaft together with the specific washer in its seat whilst keeping the return spring 4 of the movable pawl pressed. If you want to test the correct operation of the entire unit, you just need to temporarily couple the external gearshift lever and to simulate the operation of changing gears, by lifting and lowering the gearshift lever and having the main shaft of the gear unit rotate. The whole device works properly if no abnormal jamming occurs. If the unit runs without oil, the device makes more noise than usual. 64 ENGINE CHECKS AND ASSEMBLY 3.7 3 KICKSTARTER DEVICE - OPTIONAL Before coupling the kickstarter to the crankcase half, some checks must be carried out. 3.7.1 CHECKING THE KICKSTART SHAFT UNIT AND ASSEMB LY In order to disassemble all the parts of the kickstart shaft, pull off the washer 11 at the end of the shaft (on the spring side 16), the spring 16, the kickstart sleeve 14, and the lever return spring 8, which must be pulled in the radial direction so that it is extracted from its hole in order to be released from the shaft. EXPLODED VIEW OF COMPLETE KICKSTART SHAFT: 2) Kickstart gear; 3) Kickstart shaft; 8) Kickstart return spring; 9) Kickstart spacer; 10) 20E circlip; 11) Washer thickness 20x28x1 DIN 988; 12) K20x24x10 roller bearing; 14) Kickstart sleeve; 16) Spring. 65 ENGINE CHECKS AND ASSEMBLY 3 14 3 Positioning of sleeve on small shaft. Remove the kickstart spacer 9, expand the circlip 10, allowing for the removal of washer 11, of kickstart gear 2 together with roller bearing 12 and washer 11. This frees the kickstart shaft 3 from all other parts. Make sure that the side of the kickstart gear teeth 2 has no signs of meshing or notable superficial wear. Make sure that the front teeth (sleeve side 14) are not chipped. Replace any part that shows the aforementioned defects. Make sure that the front teeth of the sleeve 14 are not chipped and that the spring 16 is capable of exerting enough pressure on the sleeve 14 so that this can pull the wheel 2. Also check to make sure that no washers have any abnormal or excessive wear. If so, replace them. Make sure that the spring 8 has no cracks or abnormal deformation. Replace if it is not able to bring the external kickstart lever back to the rest position. For reassembly, follow the above disassembly procedure in reverse order. Pay attention to the correct positioning of the sleeve 14 in respect to the shaft 3. The front of the shaft has a reference sign, just as the sleeve 14 does: the two references must match. 3.7.2 Assembly of kickstarter device Insert the complete kickstart shaft in its housing, keeping the thin-striped facing outwards and making sure that the ramp A on the kickstart sleeve is positioned below the ramp B bolted onto the right crankcase half (external side). B A Positioning of sleeve A below lever B. 66 Turn the spring clockwise until it fits into the specific hole C. 3 C ENGINE CHECKS AND ASSEMBLY Insertion of kickstart return spring. Insert in the slot on the protruding segment of the secondary shaft: the circlip 18, the rose-petal 17, the idler wheel 4 followed by the rose-petal 17 and the circlip 18 as shown in the figure. Kickstart device unit coupled to the crankcase. 67 ENGINE CHECKS AND ASSEMBLY 3 3.8 COUNTERWEIGHT, PRIMARY GEAR AND CLUTCH UNIT Before reassembling the clutch unit, it is required to carry out some checks on the various components described below. 3.8.1 INSPECTION OF COUNTERWEIGHT AND PRIMARY GEAR Check that the teeth of the primary gear and the counterweight are free from nicks and traces of abnormal wear. Otherwise, replace the worn parts. 3.8.2 APPLICATION OF PRIMARY GEAR AND COUNTERWEIGHT Apply the O-ring 18, the spacer 12 and gear 14 on the right half shaft so the appropriate groove fits with the Woodruff key 17. 1 2 A 30Nm B 68 Apply the counterweight 1 on the support shaft, taking care to align the references A on the counterweight and primary gear. Apply the screw 2 on the counterweight support shaft after applying medium strength threadlocker. Keeping the primary gear/counterweight coupling firmly in place with a special tool B (code 026.14.012.50.00), tighten the screw 2 to the indicated torque. Apply the lock nut 15 after applying medium strength threadlocker; tighten at the indicated torque. 3 ENGINE CHECKS AND ASSEMBLY C 160Nm This is possible once the clutch case is inserted using the primary special tool C (code 029.14.002.50.00). See Par. 3.8.3 to apply the clutch case. AT T E N T I O N ! The nut is fastened anti-clockwise 69 ENGINE CHECKS AND ASSEMBLY 3 A B 3.8.3 CHECKING THE CLUTCH CASE, ROLLER BEARING AND INTERNAL CENTRE BEARING Before reassembling the clutch case, make sure that the sides of the teeth A, designated for main transmission and B, designated for meshing with the kickstart idler gear and oil pumps, have no superficial nicks or abnormal wear. Case gears 1 Check the condition of the internal centre bear- 2 ing 1 which must show no traces of meshing or abnormal wear. Check the condition of the roller bearing 2. If worn, it must be replaced. Centre bearing and roller bearing 70 ENGINE CHECKS AND ASSEMBLY 0 10 20 30 INC ORIGIN ON / OFF mm ZERO / ABS 100 110 120 Clutch pack measurement 3.8.4 CHECKING DISCS THE 3 CLUTCH The clutch discs are divided into driving and driven: eight driving discs and seven driven discs. The driving discs have cork inserts on both sides which wear out due to the driven discs sliding on them. One needs to check that the thickness of the clutch pack (driven and driving discs) is not lower than a minimum set value equal to: minimum thickness of complete disc pack: 31.6mm The other measurement that needs to be checked is the thickness of the teeth of each driving disc, which must not be less than the minimum set at: minimum driving disc tooth thickness: 13.3mm Also check the distortion of the driven discs. This operation is carried out by placing the driven discs on a perfectly flat surface and using a thickness gauge to check that any gap between the disc and the surface is not greater than: allowable distortion of driven discs: 0.10mm 0 10 20 30 40 ORIGIN INC ON / OFF mm ZERO / ABS 3.8.5 CHECKING THE SPRINGS To ensure the correct pressure between the clutch discs, the state of the springs must be checked. The minimum acceptable length must be: minimum clutch spring length: 45mm 71 ENGINE CHECKS AND ASSEMBLY 3 Guide pin 3.8.6 CHECKING THE CLUTCH DRUM AND CAP The clutch drum engages with the driven clutch discs by means of the sliding pins A: make sure that the area shown in the figure has no meshing or abnormal wear. If so, replace the sliding pins. A Check that the disc friction area is free from scratches, meshing or abnormal wear. If so, replace the clutch drum. Also check that the radial holes on the clutch drum are not obstructed and are free from sediments. Bare clutch drum B A Thrust bearing device. 3.8.7 CHECKING THE THRUST BEARING DEVICE Check the state of use of the thrust bearing and the surfaces upon which it rests. In order to check the thrust bearing, just ensure it slides when the device is assembled, simulate rotation of the front centre bearing A with respect to the rear one B. Carefully check for any traces of meshing or wear on the sliding surfaces. In the event of signs of deterioration, replace the entire unit. 72 ENGINE CHECKS AND ASSEMBLY 3.8.8 CLUTCH UNIT ASSEMBLY Lubricate the end of the primary gearbox shaft, the internal centre bearing 4 and the roller bearing 5. Fit the roller bearing 5 and the centre bearing 4 on the clutch case 1. Mount the unit on the primary shaft; in order to make insertion of the clutch case easier, slightly turn the kickstart idler gear (optional), the idler gear for oil pump control and the case, thus making meshing easier. Fit the washer 6, which the clutch drum 2 rests against. Fit the sliding pins 35 on the drum. Apply the safety washer 7 and, after applying medium strength threadlocker, fit the lock nut 8. 3 EXPLODED VIEW OF CLUTCH UNIT: 1) Complete case; 2) Clutch drum; 3) Clutch pressure cap; 4) Internal centre bearing; 5) 26x30x22 roller bearing; 6) Washer; 7) Safety washer; 8) M18x1.5 nut; 9) Thrust bearing assembly; 10) Clutch body rod coupling; 11) Thrust bearing; 12) RB14 circlip; 13) Clutch spring; 14) Clutch spring retainer; 15) Hex socket head tapered screw; 16) Driven discs; 17) Driving discs GREEN edge; 18) Driving disc BLUE edge; 35) Guide pin; 36) Thrust washer. 73 ENGINE CHECKS AND ASSEMBLY 3B To tighten the nut 8 the clutch drum must be held blocked with tool A (code 029.14.002.50.00). A Tighten to the specified torque. 120Nm Having tightened the nut, fold the two locking fins on the safety plate. Safety washer folding Disc arrangement Lubricate the clutch discs with gear oil and apply the driving disc with BLUE edge and a driven disc. Then alternate the driving discs with GREEN edge and the driven discs. The other BLUE driving disc will close the disc pack. Please note that the driven discs must be inserted so that the connecting radius on the teeth faces inwards towards the engine. 74 Insert the thrust bearing assembly 9 (after lubricating it with gear oil) in the hole on the gearbox main shaft and check free axial sliding. 3 ENGINE CHECKS AND ASSEMBLY Thrust bearing assembly Close the clutch unit with the clutch cap 3, the springs 13, the four spring retainers 14 and the screws 15. Clutch cap assembly A Close the clutch unit with the clutch cap 3, the springs 13, the four spring retainers 14 and the screws 15. 10Nm 6 4 2 1 3 5 75 ENGINE CHECKS AND ASSEMBLY 3 EXPLODED VIEW OF CENTRIFUGAL UNIT AND WATER PUMP UNIT 1) Rocker arm; 2) 5x15x2; 3) M5x12 screw; 4) Complete valve control rod; 5) Spring guide; 6) Auxiliary spring; 7) Adjustment spring; 8) 10x16x1 washer; 9) Roller bush; 10) Centrifugal control lever; 11) Water pump impeller; 12) Water pump washer; 15) Complete centrifugal unit; 16) Axial roller cage; 17) Centre bearing; 18) Spacer; 19) Circlip; 20) Complete centrifugal shaft; 32) Ball joint retainer ring; 33) 6x19x6 bearing; 34) 15x32x9 bearing; 35) Oil seal 3.9 COOLANT LIQUID PUMP AND CENTRIFUGAL UNIT The water pump must assure the correct flow rate of coolant, depending on the set rotation speed, in order to remove the required amount of heat from the power unit. The centrifugal unit activates the whole exhaust valve control linkage based on the engine rotation speed, while springs 6 and 7 provide the appropriate resistance to the centrifugal action generated by 20, in order to assure optimal supply of torque and power. The impeller 11 is keyed onto shaft 20 and coupling is assured by tightening nut 3 on shaft 20. The centrifugal unit shaft 20 is supported by bearing 34 found on the internal clutch cover and by bearing 33 on the external side right crankcase half. Tightness is assured by oil seal 35. 76 ENGINE CHECKS AND ASSEMBLY A View in centrifugal unit section: stroke A. 3.9.1 CHECKING THE PUMP UNIT AND DISASSEMBLY, CENTRIFUGAL UNIT AND IDLER UNIT 3 Refer to par. 2.6.1 to disassemble the entire pump unit. Check oil seal condition. Replace if worn. Check centrifugal unit shaft condition. Replace the entire centrifugal unit if dented in the area in contact with the oil seal. Check the device's axial stroke A and ensure it is between 6.4-6.6mm. Otherwise replace the unit. Remove circlip 19 and check use status of the roller axial cage 16. Replace it in case of anomalies. Exploded view of centrifugal unit. Check the roller bushes 9 do not jam during their operation and check the centrifugal control lever 10 moves correctly. Exploded view of bearings and centrifugal control lever. Also check area A of lever 10 is not worn. A Check of centrifugal control lever area A. 77 3 3.9.2 CENTRIFUGE UNIT GROUP ASS E M B LY Insert the centrifugal unit 20 in inner clutch cover. 20 ENGINE CHECKS AND ASSEMBLY Insertion of centrifugal unit. 10 Insert the centrifugal control lever 10 together with the washers 8. 8 Insertion of centrifugal control lever. 78 Apply the valve control rod gasket and the rocker arm 1 - valve control rod 4 assembly. 3 4 ENGINE CHECKS AND ASSEMBLY 1 Application of valve control and rocker arm assembly. Apply blocking screws 3 prior depositing of medium strength threadlocker. Tighten to the specified torque. 3 6Nm Centrifugal unit assembly. 79 ENGINE CHECKS AND ASSEMBLY 3 4 3 5 Spring guide and springs unit. 6 Nm Apply the auxiliary 4 and adjustment 3 springs to the spring guide 5. Apply the complete adjustment cover to the inner clutch cover. Apply the locking screws after applying medium strength threadlocker and tighten to the indicated torque. Fastening of adjustment cover. Displacement [cm3] 250 300 * Optional MY 2020 2020 The vehicles are fitted with the following auxiliary and adjustment springs. Adjustment spring Colour White Yellow Green* Auxiliary spring Colour Blue White* 80 Thicker edge 1 2 Application of the oil seal to the pump body. 1 3.9.3 PUMP UNIT ASSEMBLY Grease the oil seal housing on the pump body 1. Position the oil seal 2 so that the thicker edge faces the outside of the pump body. Insert the oil seal, having it enter the seat very slowly to prevent it from deteriorating. The oil seal edge must be at the same height as the pump body (outer side). 3 ENGINE CHECKS AND ASSEMBLY 3.9.4 ASSEMBLY OF COMPLETE CLUTCH COVER AND PUMP UNIT Apply a new gasket 1 placed between the right crankcase half and the inner clutch cover using the two reference pins 2 to keep it in place. Couple the inner clutch cover to the right crankcase half and rotate the centrifugal shaft until the shaft meshes in the main gear. 2 Positioning of gasket and reference pins. 81 3 Apply the seven screws as pictured, tightening them at 10Nm with a criss-cross pattern. ENGINE CHECKS AND ASSEMBLY Screws positioning. Number screw 6 7 8 Screw size Threading diameter Threading length M6 20 M6 30 M6 50 Threadlocker application NO NO NO Tightening torque [Nm] 10 10 10 82 Grease the O-rings on the water hose and insert the hose 4 in the right crankcase half. 3 4 ENGINE CHECKS AND ASSEMBLY Insertion of water hose. 6 7 Apply the gasket between the pump body and clutch cover. Grease the inner diameter of the oil seal on the pump body 5 and apply the body to the clutch cover. Apply washer 6 and water pump impeller 7. 5 Application of water pump impeller. 8 6Nm Apply the screw 8 after applying medium strength threadlocker and tighten at 6Nm. Complete water pump. Pump cover. 9 10Nm Couple the water pump cover to the pump body by applying the two M6x60 screws 9 and the two M6x30 screws 10. Tighten all screws at a torque of 10Nm following a criss-cross pattern. Apply the oil drain plug and tighten to 15Nm. 10 83 ENGINE CHECKS AND ASSEMBLY 31 2 10Nm 1 3.10 ELECTRIC IGNITION UNIT Carry out the following checks before assembly. 3.10.1 BENDIX COUPLING CHECKS Check wear of the gearwheels found on the unit. Replace the whole coupling in case of abnormal wear and signs of chipping of the wheels. Keep the wheel 1 fixed and rotate the mobile coupling 2 anti-clockwise; this must slide without seizing. When releasing the mobile coupling, it must go back to rest position without seizing. Replace the whole unit if anomalies are detected during these two checks. 3.10.2 IGNITION UNIT COUPLING TO ENGINE Apply a thin layer of grease on the O-ring located on the starter motor. Insert the starter motor in its seat and lock it with the two screws 1, after applying medium strength threadlocker. Tighten to the specified torque. 84 Pour about 7cc of gear oil (for specifications refer to the recommended lubricants and liquids table) in area A. 3 ENGINE CHECKS AND ASSEMBLY Application of oil. A Insert Bendix coupling 2 in bush with collar 3 3 present on the outer side left crankcase half. Insertion of Bendix coupling. 2 3.11 IGNITION SYSTEM Before reassembling the ignition system, it is recommended to make sure it is in good working order. The ignition system consists of the magnetic pick-up unit, the stator unit and the flywheel. The system is completed by the ignition coil and the spark plug, which are not dealt with here. 85 3 3.11.1 IGNITION SYSTEM CHECK Accurately degrease the various elements and carry out the checks. The main check is the one concerning the electrical inspection which can be done by using a standard tester. The measured resistance values must comply with those in the table. ENGINE CHECKS AND ASSEMBLY Element Pick up Stator 6Nm 1 Coupling of pick up to crankcase. Cables Red Green Red/Black White/Red Yellow Mass Yellow White Resistance values 100 ± 20% 14.7 ±15% 0.61 ±15% 0.18 ±15% 3.11.2 COUPLING OF IGNITION SYSTEM TO CRANKCASE Apply the pick up to the crankcase and insert the gasket in the specific seat, after applying the insulating silicone paste. Cover the threading of the two screws 1 with medium strength threadlocker and tighten them at a torque of 6Nm. Thoroughly degrease the crankshaft conical section, apply the Woodruff key 8 in the appropriate groove present on the crankshaft, couple the flywheel 9, the elastic washer 5 and the nut 4, after having spread the threading with medium strength threadlocker. 60Nm Exploded view of flywheel. 4) M12x nut; 5) Elastic washer; 8) Woodruff key; 9) Flywheel. 86 Tighten the nut to torque 60Nm, keeping the flywheel blocked with the special tool A (code 026140040 000). 3 ENGINE CHECKS AND ASSEMBLY A Flywheel fastening. 10Nm Couple the stator to the flywheel cover by means of the two screws 10. Cover the threading with medium strength threadlocker and tighten them at a torque of 10Nm. Insert the cable gland in its specific seat and check its perfect sealing. 10 Stator coupling to the flywheel cover. 11 Apply a few drops of silicone in the guides for housing the plate 1. Apply the plate 11 to be inserted in its guides and pressed. When coupling it to the left crankcase half, apply a drop of gasket paste (code 3625000000) in area B. B Application of stator plate. 87 3 12 Insert the centring pins 12 on the crankcase and fit a new gasket. ENGINE CHECKS AND ASSEMBLY Application of flywheel cover centring pins. 13 14 10Nm Apply the flywheel cover, the two M6x25 screws 13 and the three M6x20 screws 14. Tighten in a criss-cross pattern at a torque of 10Nm. Note: When performing a complete overhaul of the engine or intervening on the thermal unit, do not apply the cover as it has to be removed to find the Top Dead Centre. 14 13 Flywheel cover coupled to crankcase. 88 3.12 THERMAL UNIT Before assembling the thermal unit, thorough checks must be carried out on the cylinder, piston, pin bolt, elastic bands described hereafter. 3 ENGINE CHECKS AND ASSEMBLY X Position to measure the outside diameter of the piston. 3.12.1 CHECKING THE PISTON AND ELASTIC BANDS Remove carbon sediment from the top of the piston and wash the entire piston with specific degreasing agent. Do not use sharp points or tools for cleaning. Then carry out a careful analysis of the piston which must be free from forcing, scratches, cracks or any type of damage. Analyse the external diameter of the piston. The diameter must be measured at a distance X from the inner edge of the skirt, perpendicularly to the axis of the pin bolt. Refer to the following table for the piston's selection classes. Displacement [cm³] 250 300 Measurement X [mm] 18 18 A 66.345÷66.354 71.945÷71.954 Bore [mm] B 66.355÷66.364 71.955÷71.964 C 66.365÷66.375 71.965÷71.975 In order to check the condition of the elastic bands, the band must be inserted in the cylinder so that its axis is aligned with the axis of the cylinder. Then measure the distance between the two opposite ends. The elastic bands must be positioned at about 31 mm from the cylinder's upper edge. The respective service limits are set out in the table below. First check of elastic bands. Displacement Service limit of elastic [cm³] band [mm] 250 - 300 0.4 89 ENGINE CHECKS AND ASSEMBLY 3 3.12.2 CYLINDER CHECK Check the cylinder is without signs of seizure. Otherwise replace it. Measure the bore at a distance A from the top face of the cylinder (surface between cylinder and head). Take the correct measurement by following direction X. Displacement [cm³] 250 300 Measurement A [mm] 31.3 31.5 Bore measurement is required to know the coupling play between cylinder and piston. X A The cylinder's specific class is punched inside the expansion chamber. Cylinder class punching. 90 3 2 1 ENGINE CHECKS AND ASSEMBLY 3 3.12.3 PISTON CYLINDER COUPLING PLAY The following table sets out the coupling play between cylinder and piston. In order to calculate the coupling play between cylinder and piston, a subtraction must be carried out between the diameter of the cylinder and that of the piston. Displacement [cm³] 250 - 300 Maximum cylinder/ piston play [mm] 0.1 Minimum cylinder/ piston play [mm] 0.035 3.12.4 CHECKS AND EXHAUST VALVE UNIT DISASSEMBLY Remove the screws 1 to allow the disassembly of the exhaust flange 2 and its gasket 3. Remove screw 4 fastening the valve control unit to the booster; then remove screw 5 fixing the 4 bearings. 5 91 ENGINE CHECKS AND ASSEMBLY 36 Remove screw 6 that keeps the left side bearings and the booster in their housing. Apply one M5 screw on control unit side and pull outwards. Repeat the operation on the opposite side using one M6 screw. After extracting the boosters and relevant pin, ex- A tract the valve pin 7 by pushing it with a metal cylinder A and then extract valve 8. 7 92 3 ENGINE CHECKS AND ASSEMBLY 8 11 9 10 Check the bearings 9 supporting the booster are efficient, without seizing during operation or excessive play, once the assembly has been cleaned and descaled. Otherwise replace. Check pins 10, 11 and their seats are not abnormally worn. Otherwise replace the worn parts. Descale all passages involving the exhaust. Strictly avoid the use of abrasives. 3.12.5 EXHAUST VALVE UNIT ASSEMBLY Insert the valve 1 in its seat with the back facing upwards. 1 2 Insert pin 2 while holding valve 1 in position. 1 93 ENGINE CHECKS AND ASSEMBLY 3 3 Apply the left side booster unit complete with pin and bearings in its seat: pin 3 must be inserted in the specific slot in the valve. Apply the right side booster unit in its seat. 4 10Nm Apply screws 4 and 5 complete with washer after applying medium-resistance threadlocker and tighten at the specified torque. 5 94 10Nm 10Nm Apply spacer 5 to the control side. Then apply all other parts. Screw 6 must be covered with medium strength threadlocker and fastened to the indicated torque. Try moving the assembly and check the entire mechanism slides perfectly, once assembly is completed. 3 ENGINE CHECKS AND ASSEMBLY 6 7 8 10Nm 3.12.6 PISTON, PIN BOLT, ELASTIC BANDS AND CYLINDER ASS E M B LY Insert a circlip for retaining the pin bolt in one of the seats on the piston's side, placing the circlip's open part either upwards or downwards. Apply the roller cage in the connecting rod's foot, and lubricate it. Oil pin bolt and seat in piston. Insert the pin bolt in the piston from the side opposite where the circlip was inserted, leaving enough space to allow the connecting rod to mate with the piston. Place the piston so that the arrow stamped on the crown is facing the front of the engine (exhaust opening). Couple the piston to the connecting rod by fully pushing the pin bolt until flush with the previously inserted circlip. It may be helpful to use an aluminium cylinder (or similar tool) during this phase. WARNING! Place a clean cloth between the piston and the crankcase to keep foreign objects from falling inside the base. 95 ENGINE CHECKS AND ASSEMBLY 3 OK NO! Positioning of elastic bands on the piston. Insert the second circlip in the specific seat of the piston, placing the open part either upwards or downwards. Remove the previously inserted cloth. Abundantly oil the skirt of the piston with engine oil and insert the elastic bands, which edges must face the area with the stop pin. Apply the gasket between crankcase and cylinder. Note: keep the silicone edge facing down. Accurately oil the entire cylinder using engine oil and insert the piston in the cylinder. The piston must be inserted in the cylinder while holding the elastic bands with one's fingers tightly. The cylinder must be positioned so that the exhaust gap is facing the front of the engine. Push the cylinder towards the crankcase. Coupling of cylinder to piston and crankcase. Apply the four collar nuts and tighten them at 30Nm, following a criss-cross pattern. 30Nm Tightening of cylinder nuts. 96 ENGINE CHECKS AND ASSEMBLY 3.12.7 CHECK OF CRANKCASE/ CYLINDER GASKET THICKNESS 3 The thickness of the gasket between the cylinder and crankcase must be checked every time the following are replaced: Cylinder; Piston; Crankshaft; Connecting rod; Crankcase. The check is necessary as said thickness affects engine performance. The check must be carried out using the specific calibrated plates set out in the table. Displacement [cm³] 250 300 Model Year 2018 - 2019 Case where the plate and piston do not touch: check distance between plate and piston. Code 026.14.010.00.00 Side B A The use of the plates is described below. · Place the specific plate making sure it comes into contact with the cylinder's upper surface. · Move the piston to top dead centre and, using a thickness gauge, check the play between piston and plate is between 0÷0.05mm. If the play between piston and plate is higher than required, reduce the cylinder/crankcase gasket thickness and carry out the check again. 97 ENGINE CHECKS AND ASSEMBLY 3 Measure the play with a gauge if the piston pushes the plate upwards, causing contact to be lost between plate and cylinder: if the play is greater than 0.05 mm, the thickness of the cylinder/casing gasket must be increased and the check must be done again. Case where the piston pushes the plate causing cylinder/plate contact to be lost The gaskets are supplied in four different thicknesses. that can also be stacked, thus obtaining the necessary height for the right thickness. Note: the above-described check must be carried out once all four crankcase cylinder coupling nuts have been fastened at the set torque (30Nm). 15Nm 27Nm 3.12.8 HEAD APPLICATION Apply the two O-rings to the cylinder. Place the head so that the water hose is facing the front of the engine. Grease the screws and apply them to the head, together with the copper washers. Following a cross pattern, tighten in two steps: 1. 15Nm; 2. 27Nm Tightening of head. 98 4 Positioning of valve control. 3.12.9 EXHAUST VALVE 2 ADJUSTMENT 3 Bring the valve control unit 1 in the fully closed position, so the stroke end lever is flush with screw 2 fixing the booster bearings. 1 3 Check that the ball head 3 and the seat 4 are perfectly aligned. Otherwise loosen the lock nut, adjust the seat and tighten the lock nut. ENGINE CHECKS AND ASSEMBLY NO! NO! OK Incorrect positions of the control rod seat. Correct position of the control rod seat. 99 3 Ensure the control rod is able to rotate around its axis, making equal angles with respect to the ball head axis. ENGINE CHECKS AND ASSEMBLY Check of control rod rotation. Apply gasket 5 and insert the control rod. 5 Apply the stop 6. 6 Insertion of control rod and application of stop. 100 ENGINE CHECKS AND ASSEMBLY Intervene on screw 7 for the dynamic adjustment of the exhaust valve unit, thus modifying the characteristic curve of the engine. The positions indicated in the table below are those considered optimal for engine operation. 3 Model Year Displacement [cm³] Regulation of adjustment screw (from all open) 250 1 + 1/2 2020 7 300 1 The "fully open" position is for perfect alignment between adjustment screw head and adjustment cover. Adjustment must, therefore, be carried out as follows. Bring the screw to the "fully open" position; Tighten the number of turns indicated in the table. Fully open reference. The table shows the effects obtained from modifying the position of the adjustment screw with respect to the positions in the above table. Clockwise rotation of adjustment screw Softer flow-rate and less over-rev Anti-clockwise rotation of adjustment screw Greater acceleration and lower torque at low speeds AT T E N T I O N ! Do not tighten the adjustment screw for more than three and a half turns from the fully open position. 101 3 3.12.10 APPLICATION OF COVERS Apply the valve control unit cover and relative screws. Tighten to the specified torque. 6Nm ENGINE CHECKS AND ASSEMBLY Application and tightening of valve control unit cover screws. Apply the expansion chamber side gasket and cover. Apply the screws and tighten them to the specified torque. 6Nm Application of expansion chamber cover and screws. 102 3.13 3 CHECK OF INTAKE UNIT AND ASSEMBLY Check the manifold 1 is intact and without cracks. Otherwise replace it. Check that the petals 2 of the reed valve 3 are intact and not deformed. If so, replace them. ENGINE CHECKS AND ASSEMBLY 2 1 3 Remove the petals by pressing the central body as shown in the picture and remove the outer petals. Disassembly of reed valve body. 103 ENGINE CHECKS AND ASSEMBLY 3 Remove the two central wedges and remove the petals. Assemble the multiflap by following the just described procedure, in reverse order. Disassembly of central wedges. The extraction of only one is shown in figure. 6 For assembly of the entire intake system, apply the manifold to the reed valve, the gasket 4, the spacer 5 and another gasket. Tighten the screws 6 to the indicated torque. 4 5 Application of reed valve. 10Nm 104 ENGINE CHECKS AND ASSEMBLY 3.14 3 INSERTION OF CLUTCH ROD AND PINION SPACER Apply the pinion spacer 5 to the secondary of the gearbox 1, so that the groove is facing inside the engine. Note: check the O-ring 4 is present. If so, apply it. Insert the gearbox rod in its seat from the lower diameter side. Insertion of clutch rod. 105 ENGINE REASSEMBLY IN THE VEHICLE 4 4 ENGINE REASSEMBLY IN THE VEHICLE Insert the engine in the frame. We recommend insertion from the frame's left side. Insert the engine pins 1 and the swingarm pin 2. 2 1 Note: pay attention that the notch on the pin head is aligned with the notch on the frame. 50Nm 3 Insert the upper shock-absorber pin 3. Fasten the shock absorber pin to the indicated torque. Apply the spark plug and fasten it at 28Nm. Apply the carburettor to the manifold making the breather tubes pass in the appropriate metal cable gland. 106 Apply the head connections by passing the gas cable and part of the electrical system, as shown in the figures. 4 ENGINE REASSEMBLY IN THE VEHICLE Fixing Head connection bracket to frame. Head connection brackets to engine Engine pins Swingarm pin Fasten the nuts and bolts following the table below. Screw M8 x 16 M8 x 65 Special M16 x 245 Torque [Nm] Threadlocker 35 Mediumresistance 35 45 125 Rotate the filter box in its normal position. Apply the lower fixing screws 4 (one each side) after applying a medium-resistance threadlocker. Tighten to the specified torque. 4 35Nm Note: We recommend removing the upper screws (one each side) and apply a medium strength threadlocker. 107 4 Make sure the filter box sleeve is correctly inserted inside the carburettor, fasten the two filter box side and manifold side straps. ENGINE REASSEMBLY IN THE VEHICLE 5 6 A B 108 Remove the cap applied to the mixer tube (see page 13). Slide the tube through the tube hole 5 and connect it to the nozzle 6 on the intake manifold. AT T E N T I O N ! Ensure the tube is fitted all the way into the nozzle. Feed through the starter motor cable A behind the carburettor breather tubes as shown in the figure. Then feed through the brake light wiring B behind the carburettor vents. ENGINE REASSEMBLY IN THE VEHICLE Connect the connector 7. 4 7 Feed through the cables as shown; secure them to the metal cable gland as shown in the figure. Connect the connector 8 to the electrical system and secure the cable as shown in the figure. 8 109 ENGINE REASSEMBLY IN THE VEHICLE 4 Connect the engine ignition unit to the electrical system. The Faston connectors must be connected according to the corresponding colours (white cable with white cable, yellow cable with yellow cable). 10Nm 9 10Nm Apply the unit clutch actuator to the two 9 fixing screws. Tighten to 10Nm. Apply the gearbox lever and fasten the screw at 10Nm by applying a medium strength threadlocker. Secure the electrical system to the clutch pipe and frame as shown in the figure using plastic clamps. 10Nm Apply the start motor cable and tighten the nut to the indicated torque. Cover the connection using the specific protective cap. 110 ENGINE REASSEMBLY IN THE VEHICLE a d Apply the right radiator to the frame. The operation is easier if pipes are inserted observing the order shown in the figure. 4 c b 10Nm Apply the fixing screws and tighten them to the specified torque. Tighten the clamps indicated. 111 4 a Apply the left radiator to the vehicle. The operation is easier if pipes are inserted observing the order shown in the figure. ENGINE REASSEMBLY IN THE VEHICLE b Apply the fixing screws and tighten them to the specified torque. 10Nm Tighten the clamps indicated. Apply the radiator grids paying attention to their correct insertion. Insert the liquid coolant. Remember to keep the vehicle in vertical position. To optimize draining tilt the vehicle slightly to the right. 112 ENGINE REASSEMBLY IN THE VEHICLE 7Nm 7Nm 10 Apply the exhaust expansion by first assembling the front springs and then applying the two fixing screws. Apply the silencer and fasten the two fixing screws to the indicated torque. Fasten the expansion fixing screws to the frame at 7Nm. 4 Apply the Kickstart lever (optional). Apply the medium-strength threadlocker on the screw and tighten at 25Nm. Apply the brake pedal return spring 10. Insert the pinion in the chain and fasten it onto the gearbox outlet shaft. Assemble the relative 11 circlip 11, checking it is in its seat. Apply the pinion guard 12 and the frame side guards 13 and 14. Fasten the screws to the indicated torque and apply the fixing straps between the side guards and frame. 13 14 12 3Nm 3Nm 113 ENGINE REASSEMBLY IN THE VEHICLE 4 15 16 Place the tank on the vehicle and connect connector 15. Insert pipe 16 observing its path as shown in the figure. Push the tank towards the front and downwards. 17 10Nm Tighten the tank screws to the indicated torque. Reconnect pipe 17 to the tank. 7Nm Reconnect the tank to the carburettor and secure the tube using the specific tube straps. 114 M6x35 7Nm M6x20 7Nm Grease the rear fastener and tighten the screws at the indicated torque values. Apply the seat. 4 AT T E N T I O N ! Disconnecting the mixer tube from the intake manifold could cause air to get into the tube itself. To avoid any lubrication problems with the thermal unit and crankshaft, use fuel with a 1% blend for the first fill-up. Use the oil recommended on page 112 in the "Recommended lubricants and liquids" table. Apply the seat. Reapply the engine guard plate with the two fixing screws, once the motorcycle is removed from the stand. Tighten to the specified torque. ENGINE REASSEMBLY IN THE VEHICLE 115 TABLE OF ENGINE COMPONENTS TIGHTENING TORQUES TABLE OF ENGINE COMPONENTS FASTENING TORQUES Fixing Kickstarter lever (optional) Desmodromic control bearing fixing Securing the halfshoulders Stop cam Gear stopping device lever Gearshift lever Starter motor Securing the lever Kickstarter lever Primary transmission pinion nut Drum nut and clutch case Clutch cap Diameter x Length Quantity Threadlocker Torque [Nm] Outer side right crankcase half M6 x 20 2 Medium-strength threadlocker 10 Inner side right crankcase half M5 x 8 1 Medium-strength threadlocker 6 Crankshaft M6 x 12 1 High-strength threadlocker 5 Gearshift M6 x 30 M6 x 20 M6 x 25 1 Medium-strength threadlocker 10 1 Medium-strength threadlocker 10 1 Medium-strength threadlocker 10 Electric kickstarter device M6 x 25 2 Medium-strength threadlocker 10 Pedal kickstarter device - Optional M8 x 26 M6 x 12 1 Medium-strength threadlocker 25 2 Medium-strength threadlocker Clutch primary transmission 1 Medium-strength threadlocker 160 1 Medium-strength threadlocker 120 M6 x 25 6 10 Notes Optional Do not use pneumatic device Clutch actuator M6 x 20 2 10 Clutch actuator M6 x 30 1 10 Outer clutch cover M6 x 20 2 Outer clutch cover M6 x 50 3 Inner clutch cover M6 x 20 2 10 In common 10 with inner clutch cover 10 Inner clutch cover M6 x 30 2 10 Inner clutch cover M6 x 50 3 Inner clutch cover M6 X 60 2 116 In common 10 with outer clutch cover In common 10 with water pump cover TABLE OF ENGINE COMPONENTS FASTENING TORQUES Fixing Counterweight Cover Cover Impeller Flange Cover Complete control rocker arm Control lever Booster bearings Right cover Diameter x Length Quantity Threadlocker Torque [Nm] Counterweight unit M8 X 15 1 Medium-strength threadlocker 30 Water pump M6 x 60 2 10 Notes In common with inner clutch cover M6 x 30 2 10 M5 x 12 1 Medium-strength threadlocker 6 Exhaust valve control M6 x 20 M5 x 20 M5 x 12 M5 x 20 M6 x 16 3 Medium-strength threadlocker 10 2 Medium-strength threadlocker 6 1 Medium-strength threadlocker 6 1 Medium-strength threadlocker 6 2 Medium-strength threadlocker 10 M5 x 16 3 6 Left cover Spark plug Pick-up unit Stator Flywheel nut Cover M5 x 16 4 Ignition system M14 x 1.25 1 M5 x 12 2 M6 x 25 2 1 M6 x 20 2 6 28 Medium-strength threadlocker 6 Medium-strength threadlocker 10 Medium-strength threadlocker 60 10 Cover M6 x 25 3 10 Cylinder Cylinder nuts 4 30 Head Head screws M8 x 35 6 27 Crankcase half Crankcase half screws M6 x 50 10 10 Crankcase half screws Reed valve Cap M6 x 40 M6 x 25 3 Intake 4 Oil drain 1 10 10 15 117 TABLE OF FRAME/ENGINE TIGHTENING TORQUES TABLE OF FRAME/ENGINE TIGHTENING TORQUES Fixing Engine pins Swingarm pin Head connection bracket to frame. Front fixing Head connection brackets to engine Diameter x Length Special M16 x 245 M8 x 16 M8 x 65 Quantity Threadlocker Torque [Nm] 2 45 1 125 Medium- 4 strength 35 threadlocker 1 35 Notes TABLE OF SUPERSTRUCTURE TIGHTENING TORQUES Fixing Tank to the frame (rear fixing) Tank side panel to the radiator Diameter x pitch [mm] Length [mm] M6 x 1 30 M6 x 1 20 Quantity Threadlocker Torque [Nm] 1 10 2 7 Notes Application of grease TABLE OF SUPERSTRUCTURE FASTENING TORQUE VALUES 118 RECOMMENDED ENGINE MAINTENANCE RECOMMENDED ENGINE MAINTENANCE The required engine maintenance only depends on the level of use and respect of the periodical inspections. The following intervals refer to normal use, as long as the engine has not worked in extraordinary conditions and that periodical inspections and interventions have been correctly carried out. 30h 60h 90h Coated clutch discs I - R Clutch springs length Gearbox bearings Case / clutch hub Cylinder Piston and segments Connecting rod Crankshaft bearings Gearbox superficial appearance Water pump oil seal Exhaust valve Reed valve shims I - R - - R I - - - I - - R - - - R - - R - - I - - R - I/C - - I - Spark plug - R - I = INSPECT AND REPLACE IF REQUIRED R = REPLACE C = Cleaning RECOMMENDED LUBRICANTS AND LIQUIDS APPLICATION PRODUCT Gearbox and clutch Coolant liquid Mixer tank Fuel tank (only for running-in) Liqui Moly racing 10W50 Liqui Moly coolant ready mix raf12 plus Liqui Moly 2-STROKE MOTOR OIL, SELF-MIXING Liqui Moly 2-STROKE MOTOR OIL, SELF-MIXING * Refer to Use and Maintenance Manual for levels QUANTITY 850ml* 1300ml* 550ml* 1% mix RECOMMENDED LUBRICANTS AND LIQUIDS 119Adobe PDF Library 15.0