Service Manual060306 2500 914 0500 Onan 2EGMBB 2.5EGMBG Home Site Portable Genset Manual (03 2006)
User Manual: 914-0500 Onan 2EGMBB 2.5EGMBG HomeSite Portable Genset Service manual (03-2006)
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Page Count: 56
Service Manual
HomeSite Power
2400 (2EGMBB-5267)
3500 (2.5EGMBG-5268)
Portable Generator Set
Printed in U. S. A. 03-06 914-0500
Redistribution or publication of this document,
by any means, is strictly prohibited.
SAFETY PRECAUTIONS
a
Thoroughly read the OPERATOR’S MANUAL
before operating the generator set. Safe
operation and top performance can only be
attained when equipment is operated and
maintained properly.
The following symbols, found throughout this
manual, alert you to potentially dangerous
conditions to operators, service personnel and
equipment.
This symbol alerts you to an
immediate hazard that will result in severe
personal injury or death.
This symbol alerts you to a
hazard or unsafe practice that can result in
severe personal injury or death.
This symbol alerts you to a
hazard or unsafe practice that can result in
personal injury or damage to equipment or
property.
Electricity, fuel, exhaust, moving parts and
batteries present hazards against which
precautions must to taken to prevent severe
personal injury or death.
Exhaust Gas Is Deadly
• Operate the generator set outdoors only.
Stay away from the exhaust outlet.
• Make sure generator set exhaust will not
enter windows, doors, vents or air intakes of
adjacent buildings, vehicles or boats.
• NEVER USE THE GENERTOR SET
INSIDE a home, garage, crawl space,
barn, shed, cabin, boat, boat house, RV or
tent, or in a confined outdoor space such as
an alley, ditch, parking garage or courtyard,
or in any other space where exhaust can
accumulate. Note that HAZARDOUS
CARBON MONOXIDE LEVELS FROM
ENGINE EXHAUST CAN ACCUMULATE
INDOORS EVEN WHEN ALL WINDOWS
AND DOORS ARE OPEN AND FANS ARE
RUNNING.
Gasoline is Flammable / Explosive
• Refuel the generator set outdoors only.
• Static electric sparks caused by fuel flowing
through a service station pump nozzle can
ignite gasoline. Never fill the generator set
with a service station pump nozzle. Instead,
fill a safety tank sitting on the ground and
then slowly transfer fuel to the generator set
from the safety tank.
• DO NOT fill fuel tanks while the engine is
running. A hot engine can ignite the fuel.
• To prevent fire due to fuel leakage, always
close the fuel valve and let the generator set
cool before transporting it or storing it in a
confined space.
• DO NOT SMOKE OR ALLOW AN OPEN
FLAME near the generator set. Keep flames,
sparks, electrical switches, pilot lights,
electrical arcs, arc-producing equipment and
all other sources of ignition well away.
Generator Voltage is Deadly
• DO NOT CONNECT THE GENERATOR
SET DIRECTLY TO ANY BUILDING
ELECTRICAL SYSTEM. Back-feed could
cause electrocution of utility line workers and
damage to equipment. An approved
switching device must be used to prevent
interconnections. A trained and experienced
electrician must make electrical connections
when the generator set is used for
emergency power.
• Make sure clothing, shoes and skin are dry
when handling electrical equipment.
• Never operate the generator set in rain or
snow or when it is sitting on wet ground.
Moving Parts Can Cause Severe
Personal Injury or Death
• Before performing any maintenance on the
generator set, disconnect the spark plug
wire.
• Always keep hands away from moving parts.
• Do not wear loose clothing or jewelry while
servicing the generator set. Loose clothing
and jewelry can become caught in moving
parts. Jewelry can short out electrical
contacts causing sparks, flame and electrical
shock.
• Make sure that fasteners and clamps on the
generator set are tight. Keep guards in
position over fans, rotors, etc.
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by any means, is strictly prohibited.
SAFETY PRECAUTIONS
b
Battery Gases are explosive
• Wear safety glasses when servicing
batteries.
• Do not smoke.
• To reduce arcing when disconnecting or
reconnecting battery cables, always
disconnect the negative (–) cable of the
battery first and reconnect it last.
General Precautions
• Keep children away from the generator set.
• Wear hearing protection when near an
operating generator set.
• Keep a multi-class ABC fire extinguisher
readily at hand. Class A fires involve
ordinary combustible materials such as
wood and cloth. Class B fires involve
combustible and flammable liquids and
gaseous fuels. Class C fires involve live
electrical equipment. (ref. NFPA No. 10)
• Benzene and lead may be found in gasoline
and have been identified by some state and
federal agencies as causing cancer or
reproductive toxicity. Do not ingest, inhale or
contact gasoline.
• Used engine oils have been identified by
some state and federal agencies as causing
cancer or reproductive toxicity. Do not ingest,
inhale or contact used engine oil or its
vapors.
• Keep the generator set clean and dry at all
times. Excess grease and oil can catch fire
and/or accumulate dirt, which can cause
overheating.
• Do not store anything on the generator set,
such as oil cans, oily rags, chains or wooden
blocks. A fire could result or operation could
be adversely affected
• Do not work on the generator set when you
are mentally or physically fatigued or have
consumed alcohol or drugs.
Failure to properly follow instructions and precautions can cause
you to be seriously hurt or killed.
Follow the procedures and precautions in this manual carefully.
Improper service or repairs can create an unsafe condition that
can cause your customer or others to be seriously hurt or killed.
Follow the procedures and precautions in this manual and other
service materials carefully.
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by any means, is strictly prohibited.
TABLE OF CONTENTS
c
Title Page
SECTION 1 INTRODUCTION 1
1-1 Generator Components 1
1-2 Specifications 3
SECTION 2 DIMENSIONS AND TORQUE 4
2-1 Engine Dimensions 4
2-2 Generator Dimensions 6
2-3 Torque Specification 6
2-4 Standard Torques Specification 6
SECTION 3 MAINTENANCE 7
3-1 Maintenance Schedule 7
3-2 Engine Oil 8
3-3 Air Cleaner 9
3-4 Fuel Sediment Cup Cleaning 10
3-5 Spark Arrester 10
3-6 Spark Plug 11
3-7 Valve Clearance 12
3-8 Governor 12
SECTION 4 DISASSEMBLY AND SERVICE 13
4-1 Troubleshooting 13
4-1-1 Hard Starting 13
4-1-2 Low Power 14
4-1-3 Speed Unstable 15
4-1-4 Low Speed Voltage 16
4-1-5 Exhaust Color Abnormal 17
4-1-6 No AC Output Voltage 18
4-1-7 No DC Output Voltage 18
4-2 Preparing to Service 19
4-2-1 Safety Considerations 19
4-2-2 Special Tools 19
4-3 Disassembly Chart 20
4-4 Engine 21
4-4-1 Crankshaft / Pistion 21
4-4-2 Flywheel 27
4-4-3 Cylinder head / Valves 29
4-4-4 Recoil Starter / Fan Cover 33
4-4-5 Air Cleaner 36
4-4-6 Carburetor 37
4-5 Generator 38
4-5-1 Fuel Tank 38
4-5-2 Muffler 39
4-5-3 Generator 40
4-5-4 Control Panel 44
SECTION 5 WIRING DIAGRAMS 50
5-1 The Wiring Diagram of 2400 50
5-2 The Wiring Diagram of 3500 51
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SECTION 1. INTRODUCTION
- 1 -
1-1 Generator Components
ON/OFF
SWITCH
DC BREAKER RESET SWITCH
AC VOLTMETER
12 VOLT DC
TERMINALS
CHOKE
LEVER
FUEL
V
ALVE
AIR CLEANER
RECOIL STARTER GRIP
FUEL
GAUGE FUEL TANK CAP
EARTH
GROUND
LUG
AC BREAKER
RESET SWITCH
120VAC RECEPTACLE
(GFCI)
FIGURE 1. 2400 COMPONENT LOCATIONS
SPARK
PLUG
BOOT
MUFFLER
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SECTION 1. INTRODUCTION
- 2 -
FIGURE 2. 3500 COMPONENT LOCATIONS
MUFFLER
SPARK
PLUG
BOOT
ON/OFF
SWITCH
DC BREAKER RESET SWITCH
AC VOLTMETER
12 VOLT DC
TERMINALS
CHOKE
LEVER
FUEL
V
ALVE
AIR CLEANER
RECOIL STARTER GRIP
FUEL
GAUGE FUEL TANK CAP
EARTH
GROUND
LUG
AC BREAKER
RESET SWITCH
120VAC RECEPTACLE
(GFCI)
AC RECEPTACLE
(240VAC)
AC BREAKER
RESET SWITCH
VOLTAGE SELECT
SWITCHE
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SECTION 1. INTRODUCTION
- 3 -
1-2 Specifications
GENERATOR 2400 3500
AC OUTPUT:
Frequency (Hertz) 60 Hz 60 Hz
Voltage 120 Volts 120 / 240 Volts
Rated Power 2000 Watts 2500 Watts
Rated Current 16.6 Amps 20.8 / 10.4 Amps
DC OUTPUT: 12 VDC / 8.3 Amps 12 VDC / 8.3 Amps
ENGINE
Engine Type Single Cylinder, Forced Air Cooling, 4-Stroke
Engine Speed (RPM) 3600 3600
Fuel Gasoline Gasoline
Engine Oil Capacity 0.63 US qt (0.6 L) 0.63 US qt (0.6 L)
Spark Plug Type F7RTC F7RTC
Spark Plug Gap 0.028 in. (0.7 mm) 0.028 in. (0.7 mm)
Engine Valve Lash
(Intake / Exhaust)
0.0039 /0.006 inches
(0.10/ 0.15 mm)
0.0039 /0.006 inches
(0.10 / 0.15 mm)
Ignition Timing (fixed) 20° BTDC 20° BTDC
Starting System Recoil Recoil
Displacement 197 cc 197 cc
GENERATOR SET
Dry Weight 99.9 lb (45 kg) 106.6 lb (48 kg)
Dimensions:
Length 24.1 inches (612 mm) 24.1 inches (612 mm)
Width 19.6 inches (497 mm） 19.6 inches (497 mm）
Height 19.3 inches (490 mm) 19.3 inches (490 mm)
Fuel Tank Capacity 4.0 US gal (15 L) 4.0 US gal (15 L)
Operating Time at Rated Output 13 Hours 12 Hours
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SECTION 2. DIMENSIONS AND TORQUE
- 4 -
2-1 Engine Dimensions
2400
Part Item Factory Specification Allowable limit
Maximum speed 3750±150 rpm -
Idle speed 1400±150 rpm -
Engine
Cylinder compression 6.0-8.5 kg/cm (1.5 –
2.13 kg/in)at 600 rpm -
Cylinder Sleeve I.D. 68.015 mm
(2.6778 in)
68.165 mm
(2.6837 in)
Cylinder head Warpage - 0.10 mm
(0.004 in)
Skirt O.D. 67.985 mm
(2.6766 in)
67.845 mm
(2.6711 in)
Piston-to-cylinder clearance 0.030-0.050 mm
(0.0012-0.0020 in)
0.12 mm
(0.005 in)
Piston pin bore I.D. 18.002 mm
(0.7087 in)
18.048 mm
(0.7105 in)
Pin O.D. 17.998 mm
(0.7086 in)
17.954 mm
(0.7068 in)
Piston
Piston -to- piston pin bore
clearance 0.004-0.016 mm
(0.00016-0.0006 in)
0.06 mm
(0.002in)
Ring side clearance
Top/second/oil
0.015-0.045 mm
(0.0006-0.0018 in)
0.15 mm
(0.0006 in)
Ring end gap Top/ second
Oil
0.2-0.4 mm
(0.008-0.016 in)
1.0 mm
(0.04 in)
Piston rings
Ring Width Top/ second
Oil
1.5 mm
(0.06 in)
2.5 mm
(0.10 in)
1.37 mm
(0.054 in)
2.37 mm
(0.093 in)
Small end I.D.
(Pin End)
18.007 mm
(0.7089 in)
18.07 mm
(0.711 in)
Big end I.D.
(Crankshaft)
30.015 mm
(1.1817 in)
30.0667 mm
(1.1837 in)
Big end oil clearance 0.030-0.050 mm
(0.0012-0.0020 in)
0.12 mm
(0.0048 in)
Connecting
rod
Big end side clearance 0.1-0.7 mm
(0.004-0.028 in)
1.1 mm
(0.043 in)
Crankshaft Crankshaft O.D.
(Connecting rod Big end)
29.985 mm
(1.181 in)
29.92 mm
(1.178 in)
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SECTION 2. DIMENSIONS AND TORQUE
- 5 -
2400
Part Item Factory Specification Allowable limit
Valve Lash IN
0.10±0.02 mm
(0.004±0.001 in) -
EX 0.15±0.02 mm
(0.006±0.001 in) -
Stem O.D. IN
5.48 mm
(0.216 in)
5.318 mm
(0.2094 in)
EX 5.47 mm
(0.215 in)
5.275 mm
(0.2077 in)
Guide I.D. IN/ EX 5.50 mm
(0.217 in)
5.572 mm
(0.2194 in)
Stem clearance IN
0.02-0.044 mm
(0.0008-0.0017 in)
0.10mm
(0.004 in)
EX 0.06-0.087 mm
(0.0024-0.0034 in)
0.12 mm
(0.005 in)
Seat width 0.8 mm
(0.03 in)
2.0mm
(0.08 in)
Valves
Spring fee length 30.0 mm
(1.18 in)
28.5 mm
(1.122 in)
Cam height IN 27.7 mm
(1.09 in)
27.45 mm
(1.081 in)
EX 27.75 mm
(1.093 in)
27.5 mm
(1.083 in)
Camshaft
Camshaft O.D. 13.984 mm
(0.5506 in)
13.916 mm
(0.5479 in)
Crankcase
cover
Camshaft-holder I.D. 14.0 mm
(0.55 in)
14.048 mm
(0.5531 in)
Spark plug Gap 0.7-0.8 mm
(0.028-0.031 in) -
Resistance Primary coil 0.8-1.0 Ω -
Secondary coil 5.9-7.1 KΩ -
Ignition coil
Air gap (at flywheel) 0.4±0.2 mm
(0.016±0.008 in) -
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SECTION 2. DIMENSIONS AND TORQUE
- 6 -
2-2 Generator Dimensions
2400 (2.0 kW)
Part Item Factory specification
Main winding (R / Bu) Resistance 0.51-0.53 Ω
Field winding Resistance 40-50 Ω
Exciter winding (Bu / Bu) Resistance 3.1-3.3 Ω
DC winding (G / G) Resistance 0.4-0.6 Ω
Carbon brush Brush length 5-9 mm
3500 (2.5 kW)
Part Item Factory specification
Main windingⅠ(Br / W) Resistance 0.76-0.79 Ω
Main windingⅡ(R / Bu) Resistance 0.76-0.79 Ω
Field winding Resistance 35-45 Ω
Exciter winding (Bu / Bu) Resistance 1.5-1.7 Ω
DC winding (G / G) Resistance 0.4-0.6 Ω
Carbon brush Brush length 5-9 mm
2-3 Torque Specification
2-4 Standard Torques Specification
Part Fastener size Torque values N· m (kg· cm, lb·ft)
Cylinder head bolt 8×1.25×55 mm 26-28 (260-280, 18.8-20.2)
Pivot bolt 6×0.5 mm 8-12 (80-120, 5.8-8.7)
Pivot adjusting nut 6×1.25 mm 22-26 (220-260, 15.9-18.8)
Crankcase cover bolt 8×1.25×32 mm 24-26 (240-260, 17.4-18.8)
Connecting rod bolt 7×1.25 mm 12-14 (120-140, 8.7-17.4)
Air cleaner wing nut 6×1.0 mm 7-10 (70-100, 5.1-7.2)
Air cleaner mounting nut 6×1.0 mm 7-10 (70-100, 5.1-7.2)
Muffler mounting bolt 8×1.25 mm 20-28 (200-280, 14.5-20.2)
Oil drain bolt 10×1.5 mm 20-25 (200-250, 14.5-18.1)
Fuel tank mounting bolt/ nut 6×1.0 mm 8-12 (80-120, 5.8-8.7)
Fuel valve joint nut 10×1.25 mm 20-25 (200-250, 14.5-18.1)
Oil level switch mounting nut 10×1.25 mm 8-12 (80-120, 5.8-8.7)
Flywheel mounting nut 14×1.25 mm 80-90 (800-900, 58-865.3)
5 mm bolt, nut 4-7 (40-70, 2.9-5.1)
6 mm bolt, nut 8-12 (80-120, 5.8-8.7)
8 mm bolt, nut 20-28 (200-280, 14.5-20.2)
10 mm bolt, nut 35-40 (350-400, 14.5-20.2)
Standard torque values
12 mm bolt, nut 50-60 (500-600, 36.2-43.4)
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SECTION 3. MAINTENANCE
- 7 -
3-1 Maintenance Schedule
Periodic maintenance is essential for top
performance. Use Table 3 as a guide. Under hot or
dusty operating conditions some maintenance
operations should be performed more frequently,
as indicated by the footnotes in the table.
Keep a log of maintenance performed and the
hours run. Recording maintenance will help you
keep it regular and provide a basis for supporting
warranty claims.
Accidental starting of the generator
set during maintenance can cause severe
personal injury or death. Before performing
maintenance, disconnect the spark plug wire
from the spark plug.
A hot generator set can cause
severe burns. Always allow the generator set
to cool before performing any maintenance or
service.
TABLE 3. PERIODIC MAINTENANCE SCHEDULE
1.See GENERAL INSPECTIONS.
2.Service more frequently when used in dusty environments.
3. These items must be performed by a trained and experienced mechanic (authorized Onan dealer).
SERVICE INTERVAL
SERVICE THESE ITEMS EACH
USE
FIRST
MONTH OR
20 HOURS
EVERY 3
MONTHS OR
50 HOURS
EVERY
MONTH
EVERY 6
MONTHS OR
100 HOURS
EVERY
YEAR OR
300 HOURS
General Inspection ×1
Check Oil Level ×
Test GFCI ×
Change Engine Oil × ×
Clean Air Cleaner ×2
Clean Cylinder Cooling Fins ×2
Clean Spark Plug ×
Clean the Spark Arrestor x
Clean Fuel Sediment Cup ×3
Clean Fuel Tank ×3
Adjust Valve Clearance ×3
Check fuel line Every 2 years(Replace if necessary) 3
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SECTION 3. MAINTENANCE
- 8 -
3-2 Engine Oil
NOTE: Drain the oil while the engine is still
warm to assure rapid and complete draining.
1) Remove the oil filler cap and drain plug.
2) Drain the oil from the crankcase.
3) Reinstall the drain plug securely.
4) Add new oil up to the bottom edge of the oil
filler hole with the engine stopped and in a level
position.
5) Reinstall the oil filler cap and tighten it
securely.
Used motor oil may cause skin
cancer if repeatedly left in contact with the skin
for prolonged periods. Thoroughly wash your
hands with soap and water as soon as possible
after handling used oil.
Engine Oil Capacity 1.16 US qt (1.1 L)
Oil filler cap Oil drain bolt (M10)
Lower level
RECOMMENDED ENGINE OIL:
SAE 10W-30 is recommended for general, all
temperature use: service classification
SG·SF/CC·CD.
20W-40
10W-30
10W-40
20W-50
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SECTION 3. MAINTENANCE
- 9 -
3-3 Air Cleaner
A dirty air cleaner will restrict air flow
to the carburetor. To prevent carburetor
malfunction, service the air cleaner regularly.
Service more frequently when operating the
generator in extremely dusty areas.
Using gasoline or flammable
solvent to clean the filter element can cause a
fire or explosion. Use only soapy water or
nonflammable solvent.
Never run the generator without the
air cleaner. Rapid engine wear will result.
1) Remove the cleaner cover by unsnapping the
two spring clips. Clean more often in dusty
environments
2) Remove the two foam filter elements and
thoroughly wash them with soap and water. Let
them dry thoroughly.
3) Knead in 1 teaspoon (5 cm3) of clean engine oil
into each foam filter element. The oil should be
distributed evenly throughout each filter
elements.
4) Reinstall the filter elements, the gray filter first
(finer pores) and then the black filter (larger
pores).
5) Secure the cover with the spring clips.
AIR CLEANER ELEMENT
SOAP & WATER
DRY
ENGINE OIL
S
Q
UEEZE
AIR CLEANER COVER
CLIP
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SECTION 3. MAINTENANCE
- 10 -
3-4 Fuel Sediment Cup Cleaning
The sediment cup prevents dirt or water which may
be in the fuel tank from entering the carburetor. If
the engine has not been run for a long time, the
sediment cup should be cleaned.
1) Turn the fuel valve to the OFF position.
Remove the sediment cup, and o-ring.
2) Clean the sediment cup, and o-ring, in
nonflammable or high flash point solvent.
3) Reinstall o-ring, and sediment cup.
4) Turn the fuel valve ON and check for leaks.
Gasoline is extremely flammable
and is explosive. Do not smoke or allow flames
or sparks in the area.
After reassembly, check for leaks,
and make sure the area is dry before starting
the engine.
3-5 Spark Arrester
A hot muffler can cause severe
burns. Allow the generator set to cool before
servicing the muffler.
Refer to MAINTENANCE SCHEDULE for
scheduled spark arrester cleaning. After letting the
generator set cool down, remove the spark arrester
screen. Inspect for damage, and replace if
defective. Clean any deposits on the screen with a
wire brush. Reinstall the spark arrester, and tighten
the screw securely.
FUEL FILTER
SEDIMENT CUP
(10 mm)
FUEL VALVE
O-RING
SEDIMENT CUP
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SECTION 3. MAINTENANCE
- 11 -
3-6 Spark Plug
To ensure proper engine operation, the spark plug
must be properly gapped and free of deposits.
If the engine has been running, the spark plug and
muffler will be very hot. Be careful not to touch the
muffler or spark plug.
1) Turn off generator.
2) Remove the spark plug cap.
3) Clean any dirt from around the spark plug
base.
4) Use the wrench supplied in the tool kit to
remove the spark plug.
5) Visually inspect the spark plug. Discard it if the
insulator is cracked or chipped. Clean the
spark plug with a wire brush if it is to be reused.
6) Measure the plug gap with a feeler gauge.
Correct as necessary by carefully bending the
side electrode.
The gap should be: 0.70-0.80 mm (0.028-0.031 in).
7) Check that the spark plug washer is in good
condition, and thread the spark plug in by hand
to prevent cross-threading.
8) After the spark plug is seated, tighten with a
spark plug wrench to compress the washer.
If installing a new spark plug, tighten l/2 turn
after the spark plug seats to compress the
washer. If reinstalling a used spark plug, tighten
l/8 - l/4 turn after the spark plug seats to
compress the washer.
The spark plug must be securely
tightened. An improperly tightened spark plug
could damage the engine.
Never use spark plugs which have
an improper heat range. Use only the
recommended spark plugs or equivalent.
PLUG WRENCH
PLUG CAP
0.7-0.80mm
SIDE
ELECTRODE METAL BRUSH
SPARK PLUG TORQUE
(20N•m-25N•m)
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SECTION 3. MAINTENANCE
- 12 -
3-7 Valve Clearance
Valve clearance inspection and
adjustment must be performed with the engine
cold.
1) Remove the cylinder head cover, and set the
piston at top dead center of the compression
stroke (both valves fully closed). Pull the starter
until the piston is at top dead center of the
compression or exhaust stroke.
2) Insert a feeler gauge between the rocker arm
and valve to measure valve clearance.
3) If adjustment is necessary, proceed as follows:
a) Hold the rocker arm pivot and loosen the
pivot lock nut.
b) Turn the rocker arm pivot to obtain the
specified clearance.
c) Retighten the lock nut while holding the
rocker arm pivot.
d) Recheck valve clearance after tightening
the lock nut.
3-8 Governor
1) Take down the fuel tank.
2) Loosen the nut on the governor arm pinch bolt.
3) Move the arm until the throttle is completely
open, and hold it in that position.
4) Rotate the governor arm shaft as far as it will
go in same direction it was just moved by the
governor arm, and then tighten the governor arm
pinch bolt.
5) Whether check the arm and throttle move
smoothing.
6) Install the fuel tank.
7) Start the engine and adjust the limiting screw to
produce the standard until the engine warm up to
normal operating temperature.
IN. 0.10±0.02 mm
(0.004±0.001 in)
Standard valve
clearance EX. 0.2±0.02 mm
(0.008±0.001 in)
Idle speed 3600±150rpm
R
OC
KER ARM
PIV
O
T
LOCK NUT
10N•m-140N•m
To increase valve clearance, screw lock nut out.
To decrease valve clearance, screw lock nut in. GOVERNOR
SPRING
THR
O
TTLE
GOVERNOR
A
RM SHAFT
GOVERNOR ARM
ANTI-SURGE SPRING
NUT
LIMITING SCREW
GOVERNOR
ARM PINCH
BOLT
nut
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SECTION 4. DISASSEMBLY AND SERVICE
- 13 -
(TRY AGAIN AFTER A FEW MINUTES)
4-1 Troubleshooting
4-1-1 Hard Starting
(SEE 4-4-1)
(SEE 4-4-1)
(SEE 4-4-3)
(SEE 4-4-3)
(SEE 4-4-3)
(SEE 3-7)
(SEE 4-4-1)
(SEE 4-5-4)
(SEE 4-4-2)
(SEE 4-4-2)
(SEE 4-4-2)
(SEE 3-6)
(SEE 3-2)
HARD
STARING
FUEL SYSTEM
IGNITION
SYSTEM
COMPRESSION
SYSTEM
(SEE 3-3)
(SEE 4-4-6)
(SEE 3-4)
(ADD FUEL INTO FUEL TANK)
FUEL low
FUEL FILTER clo
gg
ed
CARBURETOR out of ad
j
ustment
A
IR FILTER dirt
y
OIL low
SPARK PLUG GAP incorrect
SPARK PLUG CAP fault
y
IGNITION COIL GAP incorrect
IGNITION COIL fault
y
START SWITCH fault
y
OIL ALERT SYSTEM fault
y
V
ALVE LASH incorrect
CYLINDER HEAD GASKET fault
y
CYLINDER HEAD BOLT fault
y
V
ALVE fault
y
CYLINDER / PISTON / PISTON RING worn
CAMSHAFT wore
ENGINE FLOODED too much fuel
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SECTION 4. DISASSEMBLY AND SERVICE
- 14 -
(ADD CLEAN FRESH FUEL INTO TANK)
4-1-2 Low Power
(CLEAN)
(SEE 4-5-2)
(SEE 3-8)
(SEE 4-4-6)
(MOVE TO “RUN” POSITION)
(SEE 3-3)
(SEE 4-4-1)
(SEE 3-6)
(SEE 4-4-1)
(SEE 3-7)
(CLEAN)
(SEE 4-4-3)
(SEE 3-4)
Low Power
FUEL SYSTEM
IGNITION
SYSTEM
COMPRESSION
SYSTEM
CARBURETOR out of ad
j
ustment
FUEL FILTER clo
gg
ed
CHOKE ROD not o
p
en
A
IR FILTER dirt
y
SPARK PLUG fault
y
CAMSHAFT worn
CYLINDER / PISTON / PISTON RING worn
V
ALVE LASH out of S
p
ec
COOLING FAN dirt
y
V
ALVE SEAT worn or dama
g
ed
COOLING CYLINDER FINS dirt
y
MUFFLER clo
gg
ed
GOVERNOR out of ad
j
ustment
OTHER
FUEL
p
oo
r
(REMOVE EXTRA LOADS)
ELECTRICAL LOADS too hi
g
h
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SECTION 4. DISASSEMBLY AND SERVICE
- 15 -
4-1-3 Speed Unstable
(SEE 4-4-2)
(SEE 4-4-1)
(SEE 3-4)
(ADD NEW FUEL INTO FUEL TANK)
(SEE 4-4-6)
(SEE 3-8)
(REPLACE)
SPEED
UNSTABLE
FUEL SYSTEM
GOVERNOR
SYSTEM
COMPRESSION
SYSTEM
FUEL low /
p
oor
q
ualit
y
/ contaminated
FUEL FILTER clo
gg
ed
CARBURETOR clo
gg
ed
GOVERNOR out of ad
j
ustment
A
NTI-SURGE SPRING incorrect
SPARK PLUG s
p
ark
p
lu
g
wire fault
y
CAMSHAFT worn
(ADD NEW OIL)
OTHER
OIL low level
(REMOVE EXTRA LOADS)
ELECTRICAL LOADS too hi
g
h
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SECTION 4. DISASSEMBLY AND SERVICE
- 16 -
4-1-4 Low Speed / Voltage
(SEE 4-5-2)
(SEE 3-8)
(PUSH CHOKE ROD)
(SEE 4-4-6)
(SEE 3-3)
LOW
SPEED /
VOLTAGE
FUEL SYSTEM
GOVERNOR
SYSTEM
CARBURETOR has wate
r
CHOKE LEVER not o
p
en
A
IR FILTER dirt
y
GOVERNOR out of ad
j
ustment
A
NTI-SURGE SPRING incorrect
MUFFLER clo
gg
ed
A
LTERNATOR tem
p
erature is too hi
g
h
OTHER
(REPLACE)
(SEE 4-5-3)
(CLEAN ALTERNATOR FAN AND END
COVER)
(REMOVE EXTRA LOADS)
ELECTRICAL LOADS too hi
g
h
(ADD NEW FUEL)
FUEL
p
oor / contaminated
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SECTION 4. DISASSEMBLY AND SERVICE
- 17 -
4-1-5 Exhaust Color Abnormal
(SEE 3-2)
(SEE 4-4-1)
(CHANGE TO FRESH FUEL)
(ADD FRESH FUEL)
(NORMAL WHEN STARTING)
(REMOVE EXTRA LOAD)
(SEE 4-4-6)
(SEE3-3)
EXHAUST
COLOR
ABNORMAL
BLACK
WHITE
CARBURETOR fault
y
LOAD excessive
A
IR FILTER dirt
y
ENGINE tem
p
erature is too low
FUEL contaminated
FUEL contaminated with oil
CYLINDER / PISTON / PISTON RING worn
OIL too much
BLUE
(CLEAN BREATHER)
BREATHER icin
g
issue
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SECTION 4. DISASSEMBLY AND SERVICE
- 18 -
4-1-6 No AC Output Voltage
4-1-7 No DC Output Voltage
(SEE 4-5-3)
(SEE 4-5-3)
(SEE 4-5-3)
(SEE 4-5-3)
(CHECK IT AND ADJUST)
NO AC
OUTPUT
VOLTAGE
STATOR MAIN COIL defective
BRUSH defective
ENGINE SPEED abnormal
EXCITATION VOLTAGE too low
A
VR defective
(RESET BREAKERS)
BREAKER tri
pp
ed
(RESET BREAKERS)
NO DC
OUTPUT
VOLTAGE
BREAKER tri
pp
ed
OTHER REASON
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SECTION 4. DISASSEMBLY AND SERVICE
- 19 -
4-2 Preparing to Service
4-2-1 Safety Considerations
There are hazards in servicing gensets. Study
Safety precautions and become familiar with the
hazards listed in table 4-1. Note the following
safeguards and ways of avoiding hazards.
• Use personal protection: Wear appropriate
protective safety equipment, such as safety shoes
and safety glasses.
• Do not wear rings or jewelry and do not wear
loose or damp clothing that might get caught in
equipment or conduct electricity.
• Reduce the hazard: A safety, order workshop
area and well-maintained reduce the hazard
potential. Keep guards and shields in place on
machinery and maintain equipment in good working
condition. Store flammable liquids in approved
containers; away form fire, flame, spark, pilot light,
switches, arc-producing equipment and other
ignition sources. Keep the workshop clean and
well-lighted and provide adequate ventilation.
• Develop safe work habits: Unsafe actions cause
accidents with tools and machines. Be familiar with
the equipment and know how to use them safely.
Use the correct tool for the job and check its
condition before starting. Comply with the warnings
in this manual and take special precautions when
working around electrical equipment. Do not work
alone if possible and take no risks.
• Be prepared for an accident: Keep fire
extinguishers and safety equipment nearby.
Agencies such as the Red Cross and public safety
departments offer courses in first aid, CPR and fire
control. Take advantage of this information to be
ready to respond to an accident. Learn to be
safety-conscious and make safety procedures part
of the work routine.
TABLE 4-1 HAZARDS AND THEIR SOURCES
Fire and
Explosion
• Leaking or spilled fuel
• Hydrogen gas from battery
• Oily rag improperly stored
• Flammable liquids improperly
stored
Burns • Hot exhaust pipes
• Hot engine and generator surfaces
Poisonous
Gas
• Operating genset where exhaust
gases can accumulate
Electrical
Shock (AC)
• Improper generator connections
• Faulty wiring
• Working in damp conditions
• Jewelry touching electrical
components
Rotating
Machinery • Fan guards not in place
Slippery
Surfaces • Leaking or spilled oil
Heavy
Objects
• Removing genset form vehicle
• Removing heavy components
4-2-2 Special Tools
Engine
A complete set of standard and metric shop tools
are required to service the engine.
Control and Generator
A complete set of standard and metric shop tools
are required to service the control and generator.
Also needed are:
Lead or dead blow hammer
Battery hydrometer
Torque wrench
VOM millimeter
Frequency meter
Armature growler
Load bank
Jumper wires
Rotor Puller
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SECTION 4. DISASSEMBLY AND SERVICE
- 20 -
4-3 Disassembly Chart
This chart is a quick-reference guide for
disassembling the product. Be sure to follow
the sequence shown here for better and safer
work.
Example:To remove the frame.
a) Remove the end cover.
b) Remove the control box.
c) Remove the fuel tank.
d) Remove the muffler.
e) Remove the frame.
GENERATOR DISASSEMBLY
FUEL TANK
MUFFLER
END COVER
CONTROL BOX
AVR
BRUSH
STATOR ROTOR
MOUNT RUBBER FRAME
ENGINE
REAR HOUSING
AIR CLEANER
CARBURATOR
RECOIL STARTER FAN COVER
FLYWHEEL STARTER MOTOR
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SECTION 4. DISASSEMBLY AND SERVICE
- 21 -
4-4 Engine
4-4-1 Crankshaft / piston
a.DISASSEMBLY/ ASSEMBLY
REASSEMBLY:
Install with the
triangle mark
toward the push
rods.
DECOMPRESSOR
WEIGHT
REASSEMBLY:
Check that the decompressor
weight moves smoothly, and
the spring is not weak or worn.
REASSEMBLY:
Install the tappets
immediately
before installing
the camshaft.
REASSEMBLY:
Push in until the bearing
touches the crankcase. Be
careful not to damage the oil
seal.
REASSEMBLY:
Install with the oil dipper
toward the camshaft .
The ribs on the cap and
connecting rod must be
aligned.
CRANKSHAFT
CONNECTING ROD CAP
OIL LEVER SWITCH
Crankshaft
VALVE LIFTER
PISTON
OIL ALERT UNIT
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SECTION 4. DISASSEMBLY AND SERVICE
- 22 -
b.PISTON/ PISTON RING
MARKING
PISTON
PISTON PIN
PISTON PIN
REASSEMBLY:
Install the connecting rod
with the long end toward the
triangle marked side of the
p
iston.
REASSEMBLY:
Install by setting one end of the clip
in the piston groove, holding the
other end with long-nosed pliers,
and rotating the clip in. Do not align
the end gap of the clip with the
cut-out in the piston pin bore.
PISTON PIN CLIP
REASSEMBLY:
1) Install all rings with the markings facing upward.
2) Be sure that the top (chrome plated) and second rings are not interchanged.
3) Check that the rings rotate smoothly after installation.
4) Space the piston ring end gaps 120 degrees apart, and do not align the gaps with the
piston pin bore.
PISTON RING
TOP RING
(CHROME PLATED)
OIL RING
SECOND RING
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SECTION 4. DISASSEMBLY AND SERVICE
- 23 -
c.CAMSHAFT/ CRANKSHAFT
CRANKSHAFT
d.OIL LEVEL SWITCH
Ckeck continuity of the switch with an ohmmeter.
1) Hold the switch in its normal position. The
ohmmeter should read zero resistance.
2) Hold the switch upside down. The ohmmeter
should read infinity (∞) resistance.
3) Inspect the float by dipping the switch into a
container of oil. The ohmmeter reading should
go from zero to infinty as the switch is lowered.
REASSEMBLY:
Align the index marks on the
camshaft and timing gear.
CRANKSHAFT
CAMSHAFT
INDEX MARKS
(ON)
(OFF)
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SECTION 4. DISASSEMBLY AND SERVICE
- 24 -
d.INSPECTION
CYLINDER ID(Inside Diameter)
Factory Specification Allowable limit
68.015 mm
(2.6778 in)
68.165 mm
(2.684 in)
PISTON SKIRT OD(Outside Diameter)
Factory Specification Allowable limit
67.985 mm
(2.6766 in)
67.845 mm
(2.6711 in)
PISTON-TO CYLINDER CLEARANCE
Factory Specification Allowable limit
0.03-0.05 mm
(0.0012-0.002 in)
0.12 mm
(0.005 in)
PISTON RING SIDE CLEARANCE
Factory
Specification Allowable limit
0.030-0.060 mm
(0.0012-0.0024 in)
0.15 mm
(0.006 in)
PISTON RING END GAP
Factory
Specification Allowable limit
0.2-0.4 mm
(0.008-0.016 in)
1.0 mm
(0.04 in)
PISTON PIN OD
Factory
Specification Allowable limit
17.998 mm
(0.7086 in)
17.954 mm
(0.7068 in)
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 25 -
PISTON PIN BORE ID
Factory
Specification Allowable limit
18.002 mm
(0.7087 in)
18.048 mm
(0.7105 in)
PISTON-TO-PISTON PIN BORE CLEARANCE
Factory
Specification Allowable limit
0.004.016 mm
(0.00016-0.0006 in)
0.08 mm
(0.0.003 in)
CONNECTING ROD SMALL END ID
Factory
Specification Allowable limit
18.006 mm
(0.7089 in)
18.07 mm
(0.711 in)
CONNECTING ROD BIG END ID
Factory
Specification Allowable limit
30.015 mm
(1.1817 in)
30.066 mm
(1.1837 in)
CRANKPIN OD
Factory
Specification Allowable limit
29.985 mm
(1.181 in)
29.92 mm
(1.178 in)
CONNECTING ROD BIG END SIDE CLEARANCE
Factory
Specification Allowable limit
0.1-0.7 mm
(0.0040.028 in)
1.1 mm
(0.043 in)
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 26 -
CAMSHAFT DIAMETER
Factory
Specification Allowable limit
IN 27.7 mm (1.09in) 27.45 mm
(1.081 in)
EX 27.75 mm
(1.093 in)
27.50mm
(1.083 in)
CAMSHAFT CAM DIAMETER
Factory
Specification Allowable limit
13.984 mm
(0.5506 in)
13.916 mm
(0.5479 in)
CAMSHAFT HOLDER ID
Factory
Specification Allowable limit
14.00 mm
(0.55 in)
16.048 mm
(0.5531 in)
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 27 -
4-4-2 Flywheel
a.DISASSEMBLY/ ASSEMBLY
WOODRUFF KEY
REASSEMBLY:
After installing the flywheel, check
to be sure that the woodruff key is
still in its slot on the crankshaft.
SPARK PLUG LEAD
REASSEMBLY:
Check for cracked or damaged
insulation; replace if necessary.
SPARK PLUG LEAD
REASSEMBLY:
Clamp securely to the crankcase
with the two clamps.
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SECTION 4. DISASSEMBLY AND SERVICE
- 28 -
b. INSPECTION
AIR GAP (AT FLYWHEEL)
Measure the air gap between of the ignition and
flywheel by thickness gauge.
A
ir gap
(at flywheel)
0.4±0.2 mm
(0.016±0.008 in)
IGNITION COIL RESISTANCE
1. Measure the resistance of the primary coil by
attaching one ohm-meter lead to the ignition
coil’s primary lead while touching the other test
lead to the iron core.
2. Measure the resistance of the secondary side
of the coil by removing the spark plug cap and
touching one test lead to the spark plug lead
wire while touching the other test lead to the
iron core.
NOTE: A false reading will result if the spark plug
cap is not removed.
If the resistance is not as specified, replace the
ignition coil.
SPARK PLUG CAP
Measure the resistance of the spark plug cap by
attaching one ohm-meter.
If the resistance is not as specified, change the
spark plug cap.
Spark Plug Cap 5K
Primary side resistance value 0.8-1.0 Ω
Secondary side resistance value 5.9-7.1 KΩ
0.4± 0.2 mm
(0.016± 0.008 in)
IGNITION COIL
FLYWHEEL
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SECTION 4. DISASSEMBLY AND SERVICE
- 29 -
4-4-3 Cylinder Head / Valves
a.DISASSEMBLY/ ASSEMBLY
CYLINDER HEAD GASKET
CYLINDER HEAD
CRANKCASE
CYLINDER
HEAD BOLT
CYLINDER HEAD BOLT
REASSEMBLY:
Before installation, remove carbon deposits from
the combustion chamber and inspect the valve
seats.
Measure the compression of the cylinder head
after reassembly.
TORQUE:
26-28 N· m (260-280 kg· cm, 18.7-20.2 ft· lb)
REASSEMBLY/ DISASSEMBLY:
Tighten and untighten using a cross pattern.
CYLINDER HEAD
COVER GASKET
CYLINDER HEAD COVER BOLT
CYLINDER HEAD
COVER
CYLINDER HEAD COVER BOLT
TORQUE:
12-14 N· m (120-140 kg· cm, 8.7-17.4 ft· lb)
REASSEMBLY/ DISASSEMBLY:
Tighten and untighen using a cross pattern.
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SECTION 4. DISASSEMBLY AND SERVICE
- 30 -
EXHAUST VALVE
SPARK PLUG
ROCKER ARM
VALVE ROTATOR
REASSEMBLY:
Do not interchange
with the exhaust valve.
VALVE HEAD
DIAMETER:
IN: 24 mm
(0.94 in)
EX: 22 mm
(0.87 in)
REASSEMBLY:
Before installation, remove
carbon deposits and inspect
the valve.
INTAKE VALVE
DISASSEMBLY:
Compress the value spring and slide the retainer
out to the side, so the valve stem slips through
the hole at the side of the retainer.
Do not remove the valve spring
retainers while the cylinder head is installed, or
the valves will drop into the cylinder.
REASSEMBLY:
If the valve
rotator is not installed, the
valve may drop into the
cylinder when starting the
engine.
REASSEMBLY:
Check both ends for
wear and check the
rod for straightness.
Be sure the rod ends
are firmly seated in the
lifter.
PUSH ROD
REASSEMBLY:
Check the pivot bolt,
push rod and rocker
arm before installing.
REASSEMBLY:
Before installation, clean
and adjust the spark plug.
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SECTION 4. DISASSEMBLY AND SERVICE
- 31 -
b.INSPECTION
CYLINDER HEAD
Remove carbon deposits from the combustion
chamber. Clean off any gasket material from the
cylinder head surface.
Check the spark plug hole and valve areas for
cracks.
Check the cylinder head for warpage with a straight
edge and a feeler gauge.
VALVE SEAT WIDTH
Measure the valve seat width.
If the valve seat width is under the factory section,
or over the service limit, recondition the valve seat.
VALVE GUIDE ID
NOTE: Ream the valve guides to remove any
carbon deposits before measuring.
Measure and record each valve guide I. D.
Factory Specification Allowable limit
5.50 mm (0.217 in) 5.572 mm (0.2193 in)
Replace the cylinder header if they are over the
allowable limit.
GUIDE TO STEM CLEARANCE
Subtract each valve stem O.D. from the
corresponding guide I.D. to the stem to guide
clearance.
Factory
Specification Allowable limit
IN 0.02-0.044 mm
(0.0008-0.0016 in)
0.10 mm
(0.004 in)
EX 0.06-0.087 mm
(0.0002-0.0034 in)
0.12 mm
(0.005 in)
If the stem to guide clearance exceeds the
Allowable limit, determine if the new guide with
standard dimensions would bring the clearance
within tolerance. If so, replace any guide as
necessary and ream to fit. If the stem to guide
clearance exceeds the allowable limit with new
guides, replace the valves as well.
NOTE: Recondition the valve seats whenever the
valve guides are replaced.
Allowable limit 0.1 mm (0.004 in)
Factory
Specification Allowable limit
0.8 mm (0.03 in) 2.0 mm (0.08 in)
STRAIGHT EDGE
FEELER GAUGE
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SECTION 4. DISASSEMBLY AND SERVICE
- 32 -
VALVE STEM OD
Inspect each valve for face irregularities, bending or
abnormal stem wear. Replace the valve if
necessary. Measure and record each valve stem
O.D.
Factory
Specification Allowable limit
IN 5.48 mm (0.216 in) 5.318 mm
(0.2093 in)
EX 5.44 mm (0.214 in) 5.275 mm
(0.2077 in)
Replace the valves if their O.D. is smaller than the
allowable limit.
VALVE SPRING FREE LENGTH
Measure the free length of the valve springs.
Replace the springs if they are shorter than the
allowable limit.
Factory
Specification Allowable limit
30.0 mm (1.18 in) 28.5 mm (1.122 in)
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SECTION 4. DISASSEMBLY AND SERVICE
- 33 -
4-4-4 Recoil Starter / Fan Cover
a.DISASSEMBLY/ ASSEMBLY
FLANGE NUT 16mm
REASSEMBLY:
Install by aligning the three lugs on the rear
side of the fan with the small hole in the
flywheel.
When disassembling and assembling, take
care not to damage the fan blades.
COOLING FAN
RECOIL STARTER ASSY
REASSEMBLY:
Install with the starter grip position
as shown.
DISASSEMBLY/ REASSEMBLY:
Remove and install with the recoil
starter ASSY.
FAN COVER
DISASSEMBLY/ REASSEMBLY:
Hold the flywheel by placing a
screwdriver into the pulley.
STARTER PULLEY
REASSEMBLY:
Install by aligning the hole in the
pulley with the lug on the cooling
fan.
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SECTION 4. DISASSEMBLY AND SERVICE
- 34 -
b.DISASSEMBLY (RECOIL STARTER ASSY)
The recoil starter can cause personal injury, Wear safety glasses. Do not let the recoil spring
snap.
STARTER ROE
REASSEMBLY:
Install with the starter grip position
as shown.
REEL COVER
REASSEMBLY:
Align the ratchet with the reel cover
notch.
REASSEMBLY:
Install on the starter case after
installing the return spring.
STARTER REEL
REASSEMBLY:
Check for wear or damage.
Note the installation direction.
RATCHET
REASSEMBLY:
Hook the outer hook in the groove
of the starter reel and inner hook on
the starter case tab.
RETURN SPRING
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SECTION 4. DISASSEMBLY AND SERVICE
- 35 -
c.RECOIL STARTER ASSEMBLY
Wear gloves and eye wear to protect
your hands and eyes.
Do not let the return spring jump.
a) Hook the spring outer hook in the reel groove,
and install the reel on the starter case, so that
the spring inner hook is hooked to the starter
case tab by turning the reel counterclockwise.
b) Feed the end of the rope through the hole in
the starter reel, and tie the rope end. Wind the
rope onto the direction shown, and wedge the
rope end in the notch on the edge of the reel.
c) With a short length of the rope extending from
the starter reel notch, pull the end of the rope
out of the case, feed it through the starter grip,
and tie a knot in the end of the rope.
d) Install the friction plates, friction spring, ratchet
pin, guide plate, and reel cover. Tighten the
reel cover bolt.
e) Rotate the reel three full turns in the direction of
the arrow.
f) Check the operation of the ratchet by pulling
the starter rope out several times.
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SECTION 4. DISASSEMBLY AND SERVICE
- 36 -
4-4-5 Air Cleaner
DISASSEMBLLY/ REASSEMBLY
BREATHER TUBE
AIR CLEANER GASKET
REASSEMBLY:
Make sure the gasket is not
damaged, broken or bent. Install
correctly as shown.
AIR CLEANER COVER
REASSEMBLY:
Make sure to seat the gasket in the
groove on the edge of the case all
the way around properly.
REASSEMBLY:
Connect between the air cleaner
case and tappet cover.
ELEMENT
SEPARATOR
SEAL
AIR CLEANER CASE
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SECTION 4. DISASSEMBLY AND SERVICE
- 37 -
4-4-6 Carburetor
DISASSEMBLLY/ REASSEMBLY
Gasoline is flammable and explosive. Close the fuel shut off valve, and drain the carburetor
before servicing the carburetor.
CARBURETOR BODY
REASSEMBLY:
Clean internal passages and
orifices with compressed air before
installing.
REASSEMBLY:
Check for correct installation.
O-RING
REASSEMBLY:
Check for smooth movement
after installing.
FLOAT
REASSEMBLY:
Clean thoroughly with
compressed air before
installation.
MAIN NOZZLE
MAIN JET
REASSEMBLY:
Clean thoroughly with
compressed air before
installation.
FLOAT VALVE
REASSEMBLY:
Check for worn valve or
weak spring before
installation.
REASSEMBLY:
Check the screw head
for wear or damage
before installing. INITIAL
OPENING: 1-5/8 turns
out.
PILOT SCREW
REASSEMBLY:
After assembly, check for
any sign of fuel leakage.
SET BOLT
DRAIN SCREW
REASSEMBLY:
Clean thoroughly with
compressed air and check
for leaks after installation.
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SECTION 4. DISASSEMBLY AND SERVICE
- 38 -
4-5 Generator
4-5-1 Fuel Tank
DISASSEMBLLY/ REASSEMBLY
Gasoline is flammable and explosive. Drain the fuel tank and fuel line before disassembly.
Wipe up spilled fuel immediately.
REASSEMBLY:
After reassembly, check
the operation of the float.
FUEL METER
REASSEMBLY:
Make sure the passages
are not clogged.
Check for fuel leakage
after installation.
FUEL VALVE
REASSEMBLY:
Wash to remove sediment.
and dry thoroughly before
installation.
SEDIMENT CUP
REASSEMBLY:
Make sure that the air vent
hole is clean and
unclogged. Blow with
compressed air if
necessary.
FUEL TANK CAP
REASSEMBLY:
Check to be sure the
strainer is clean and
undamaged before
installation.
FUEL STRAINER
REASSEMBLY:
Wash the tank to
remove sediment,
FUEL TANK
REASSEMBLY:
Check to be sure the filter is
clean and undamaged.
FUEL FILTER
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 39 -
4-5-2 Muffler
DISASSEMBLLY/ REASSEMBLY
EXHAUST PIPE
REASSEMBLY:
Install after removing
the carbon deposits
from the muffler using
a plastic hammer.
MUFFLER
REASSEMBLY:
Install after removing the
carbon deposits from the
exhaust pipe.
EXHAUST PIPE
REASSEMBLY:
Attach after removing the
carbon from the screen with a
wire brush.
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 40 -
4-5-3 Generator
a. DISASSEMBLLY/ REASSEMBLY
GENERATOR ASSY
CRANKCASE GROMMET
REASSEMBLY:
Wipe dirt or oil off the tapered
portion of the rotor and
crankshaft before installing.
REASSEMBLY:
Check to be sure the grommet
is inserted securely.
REASSEMBLY:
43-47 N·m (430-470 kg·cm,
31.0-33.9 ft·lb)
ROTOR BOLT
DISASSEMBLY:
Remove the brush holder
before the rotor and stator.
BRUSH HOLDER ASSY
REASSEMBLY:
Tighten in crisscross pattern
in 2-3 steps.
After tightening, make sure
there is no clearance
between the crankcase
cover and stator cover.
8-12 N·m (80-120 kg·cm,
5.8-8.7 ft·lb)
STATOR BOLT
REASSEMBLY:
Insert the alignment tabs onto the holes.
Make sure the rubber is not chipped, hard or worn.
Note the installation direction.
RUBBER MOUNT
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 41 -
REAR HOUSING
ROTOR
DISASSEMBLY:
Install the appropriate rotor puller (special tool), hold the
flywheel and torque the puller to 6.9 Kg-cm (50 ft-lb).
To avoid damaging the rotor, place a wooden
block and a shop rag under the rotor for support.
NOTE:
If torquing the rotor puller does not free the rotor from the
crankshaft, tap the end of the puller with a brass hammer to
help loosen the rotor.
To prevent eye injury, always wear safety
glasses or goggles when striking the end of the rotor puller.
STATOR
STATOR COVER
GENERATOR
COOLING FAN
GENERATOR END COVER
AC OUTPUT TERMINAL
AVR ASSY
BRUSH HOLDER ASSY REAR HOUSING
Redistribution or publication of this document,
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SECTION 4. DISASSEMBLY AND SERVICE
- 42 -
b. INSPECTION
CARBON BRUSH/ SLIP RING
Remove the carbon brushes from the brush holder.
Check the brush for length, wearing condition or
any other defect. Replace if the length is less than
5 mm (0.20in).
NOTE:
z Connect the Blue wire lead to the positive (+)
side of the brush holder.
z Avoid damaging the brushes when removing
and installing the brush holder.
Visually inspect the slip rings for dust, rust or other
damage. If necessary, wipe them with a clean
lint-free cloth. If they are rusted or damaged,
remove the rotor and rub with fine emery cloth.
FIELD WINDING
Remove the brushes and measure resistance
between the slip rings.
If the specified resistance is obtained at the slip
rings, but not at the brush terminals, clean or
replace the brushes.
If the specified resistance is not obtained at the slip
rings, clean or replace the rotor.
2400 40-50 Ω
RESISTANCE
2500 35-45 Ω
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by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 43 -
MAIN WINDING
Using an ohmmeter, measure the resistance
between the AC output terminals.
NOTE:
Set the voltage selector switch to 120 V only
position.
If the resistance is zero or infinity, replace the stator.
EXCITER WINDING
Using an ohmmeter, measure the resistance
between the Light green/ Red and Green wires in
the 4P coupler.
If the resistance is zero or infinity, replace the stator.
DC WINDING
Using an ohmmeter, measure the resistance
between the brown wire leads at the DC diode
connecter.
If the resistance is out of specification, replace the
stator.
2400 0.51-0.53 Ω
3500（Ⅰ） 0.76-0.79 Ω
RESISTANCE
3500（Ⅱ） 0.76-0.79Ω
2400 3.1-3.3 Ω
3500 1..5-1.7 Ω
RESISTANCE
Slip ring -
Ground ∝
RESISTANCE 0.4-0.6 Ω
Br
W
R
Bu
AC OUTPUT
TERMINALS
3500
Br
(Ⅰ)
W
R (Ⅱ)
Bu
2400
AC OUTPUT
TERMINALS
Br
W
Br
W
Redistribution or publication of this document,
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SECTION 4. DISASSEMBLY AND SERVICE
- 44 -
4-5-4 Control Panel
a. DISASSEMBLLY/ REASSEMBLY
GENERATOR END COVER
CONTROL PANEL
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 45 -
2400
PANEL END COVER
VOLTMETER
AC BREAKER
RESET SWITCHES
DC BREAKER
RESET SWITCH
ON/STOP
SWITCH
12 Volt DC
Terminals
PANEL FRONT COVER
EARTH
GROUND
LUG
GFCI
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 46 -
3500
PANEL END COVER FUSE AND FUSE COVER VOLTAGE
SELECTOR WITCH
VOLTMETER
AC BREAKER
RESET SWITCH
AC BREAKER
RESET SWITCHES
DC BREAKER
RESET SWITCH
START/ON/STOP
SWITCH
AC RECEPTACLE
(120/240VAC)
12 Volt DC
Terminals
PANEL FRONT COVER
EARTH
GROUND
LUG
GFCI
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 47 -
2400
EXCITER WINDING 4P COUPLER
1) Red (+)
2) Blue (-)
Blue
(
+
)
GROUND CABLE
AC OUTPUT
TERMINAL STRIP
3) Blue
4) Green
5) White
DC DIODE 4P COUPLER
AVR
Yellow (-)
Brown
White
Brown
White
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 48 -
3500
GROUND CABLE
Brown
White
Red
Blue
AC OUTPUT
TERMINAL STRIP
DC DIODE 4P COUPLER
AVR
Brown
White
Red
Blue
Yellow (-)
Blue (+)
Main Winding(Ⅰ)
Main Winding(Ⅱ)
1) Red (+)
2) Blue (-)
EXCITER WINDING 4P COUPLER
3) Blue
4) Green
5) White
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 4. DISASSEMBLY AND SERVICE
- 49 -
b. INSPECTION
ENGINE SWITCH
Check for continuity between the terminals with the
switch in each position.
Yellow/
Black Black Green/
White
Green/
White Red White
Wire
Position
IG E FS G L L
OFF
ON
When switch to “OFF” position, IG is connecting to
E. When switch to “ON” position, L is connecting to
L.
DC BREAKER RESET SWITCH
Check continuity between the breaker terminals.
There should be continuity with the breaker button
pushed in.
AC BREAKER RESET SWITCHES
Check continuity between the breaker terminals.
There should be continuity with the breaker button
pushed in.
VOLTMETER
Using an ohmmeter, check for continuity between
the terminals.
Continuity should exist between them.
AC RECEPTACLE
Connect the terminals of the receptacles with a
piece of wire.
Using an ohmmeter, check for continuity between
the terminals.
If there is no continuity, the receptacle is defective,
and must be replaced.
E L
BAT
L FS IG
G
ST
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by any means, is strictly prohibited.
SECTION 5. WIRING DIAGRAMS
- 50 -
5-1 The Wiring Diagram of 2400
0
300
100
200
V
~
+
-
EIG
OFF
ON
Br
Y
Lg
Bl
W
G
R
Bu Light green
Brown
Yellow
Black
White
Green
Red
Blue
Redistribution or publication of this document,
by any means, is strictly prohibited.
SECTION 5. WIRING DIAGRAMS
- 51 -
5-2 The Wiring Diagram of 3500
+
-
EIG
OFF
ON
Br
Y
Lg
Bl
W
G
R
Bu Light green
Brown
Yellow
Black
White
Green
Red
Blue
Redistribution or publication of this document,
by any means, is strictly prohibited.
Cummins Power Generation
1400 73rd Avenue N.E.
Minneapolis, MN 55432
763–574–5000
Fax: 763–528–7229
Cummins and Onan are registered trademarks of Cummins Inc.
Redistribution or publication of this document,
by any means, is strictly prohibited.
