Onan MicroLite 4000 Series Service manual

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MicroLite 4000 Series

Printed U.S.A.

981-0503

297

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Table of Contents

SECTION TITLE PAGE

SAFETY PRECAUTIONS iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 INTRODUCTION 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2 SPECIFICATIONS 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 DIMENSIONS AND CLEARANCES 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 TORQUE SPECIFICATIONS 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 PREPARING FOR SERVICE 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Special Tools 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety Considerations 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Set Removal Guidelines 5-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6 TROUBLESHOOTING 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generator Troubleshooting 6-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Engine Primary Systems Troubleshooting 6-32. . . . . . . . . . . . . . . . . . . . . . . . . .

7 CONTROL 7-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 7-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control Description 7-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control Operation 7-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control Component Tests 7-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8 PRIMARY ENGINE SYSTEMS 8-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 8-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cooling System 8-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Exhaust System 8-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ignition System 8-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crankcase Ventilation System 8-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Governor 8-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gasoline Fuel System 8-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LPG Fuel System 8-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electric Starter 8-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The engine exhaust from this product

contains chemicals known to the State

of California to cause cancer, birth

defects or other reproductive harm.

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9 GENERATOR 9-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generator Description 9-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generator Operation 9-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generator Service 9-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generator Testing 9-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Voltage Regulator (VR1) Test 9-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brushes and Slip Rings 9-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rotor Bearing Replacement 9-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10 ENGINE BLOCK ASSEMBLY 10-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 10-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Leak Down Test 10-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oil Pan and Oil Level Switch 10-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Head Cover 10-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rocker Arms, Push Rods and Cylinder Head 10-3. . . . . . . . . . . . . . . . . . . . . . .

Valve System 10-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crankcase Cover 10-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Governor 10-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Camshaft, Tappet and Balancer Removal 10-9. . . . . . . . . . . . . . . . . . . . . . . . . .

Piston and Crankshaft 10-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inspection of Engine Parts 10-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Piston and Crankshaft Installation 10-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bearings 10-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oil Seal 10-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Compression Release System 10-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11 SERVICE CHECKLIST 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mounting 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wiring 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial Start Adjustments 11-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Exhaust System 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel System 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Output Check 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mechanical 11-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12 WIRING SCHEMATIC/DIAGRAM 12-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Safety Precautions

Thoroughly read the SERVICE MANUAL before servicing the genset. Reliable service can be obtained only with close adherance to the procedures in this manual.

The following symbols in this Manual alert you to potential hazards to the operator, service person and equipment.

Alerts you to an immediate hazard which

will result in severe personal injury or death.

WARNING

Alerts you to a hazard or unsafe practice

which can result in severe personal injury or death.

CAUTION

Alerts you to a hazard or unsafe practice which can result in personal injury or equipment damage.

Electricity, fuel, exhaust, moving parts and batteries present hazards which can result in severe personal injury or death.

GENERAL PRECAUTIONS

• Keep ABC fire extinguishers handy.

• Make sure all fasteners are secure and torqued prop-

erly.

• Keep the genset and its compartment clean. Excess oil and oily rags can catch fire. Dirt and gear stowed in the compartment can restrict cooling air.

• Before working on the genset, disconnect the negative (–) battery cable at the battery to prevent starting.

• Use caution when making adjustments while the genset is running—hot, moving or electrically live parts can cause severe personal injury or death.

• Used engine oil has been identified by some state and federal agencies as causing cancer or reproductive toxicity. Do not ingest, inhale, or contact used oil or its vapors.

• Benzene and lead in some gasolines have been identified by some state and federal agencies as causing cancer or reproductive toxicity. Do not ingest, inhale or contact gasoline or its vapors.

• Do not work on the genset when mentally or physically fatigued or after consuming alcohol or drugs.

• Carefully follow all applicable local, state and federal codes.

GENERATOR VOLTAGE IS DEADLY!

• Generator output connections must be made by a qualified electrician in accordance with applicable codes.

• The genset must not be connected to the public utility or any other source of electrical power. Connection could lead to electrocution of utility workers, damage to equipment and fire. An approved switching device must be used to prevent interconnections.

• Use caution when working on live electrical equipment. Remove jewelry, make sure clothing and shoes are dry and stand on a dry wooden platform on the ground or floor.

FUEL IS FLAMMABLE AND EXPLOSIVE

• Keep flames, cigarettes, sparks, pilot lights, electrical arc-producing equipment and switches and all other sources of ignition well away from areas where fuel fumes are present and areas sharing ventilation.

• Fuel lines must be secured, free of leaks and separated or shielded from electrical wiring.

• Use approved non-conductive flexible fuel hose for fuel connections at the genset.

ENGINE EXHAUST IS DEADLY!

• Learn the symptoms of carbon monoxide poisoning in this Manual.

• Never sleep in the vehicle while the genset is running unless the vehicle has a working carbon monoxide detector.

• The exhaust system must be installed in accordance with the genset Installation Manual.

• Do not use engine cooling air to heat the vehicle interior.

• Make sure there is ample fresh air when operating the genset in a confined area.

MOVING PARTS CAN CAUSE SEVERE PERSONAL

INJURY OR DEATH

• Do not wear loose clothing or jewelry near moving parts such as PTO shafts, fans, belts and pulleys.

• Keep hands away from moving parts.

• Keep guards in place over fans, belts, pulleys, etc.

BATTERY GAS IS EXPLOSIVE

• Wear safety glasses and do not smoke while servicing batteries.

• When disconnecting or reconnecting battery cables, always disconnect the negative (–) battery cable first and reconnect it last to reduce arcing.

MBL-2

iii

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1. Introduction

This is the service manual for the KY 4000 Series MicroLite generator sets (gensets). Read and carefully observe all of the instructions and precautions in this manual.

WARNING

Improper service or parts replacement can lead to severe personal injury or death and to damage to equipment and property. Service personnel must be qualified to perform electrical and mechanical service.

WARNING

Unauthorized modifications or replacement of fuel, exhaust, air intake or speed control system components that affect engine emissions are prohibited by law in the State of California.

WARNING

LPG (liquified petroleum gas) is flammable and explosive and can cause asphyxiation. NFPA 58, Section 1.6 requires all persons handling LPG to be trained in proper handling and operating procedures.

See the Operator’s Manual for instructions concerning operation, maintenance and storage and for recommendations concerning engine lubricating oil and fuel.

See the Installation Manual for important recommendations concerning the installation and for a list of the installation codes and standards for safety which may be applicable.

NAMEPLATE WITH TYPICAL MODEL AND

SERIAL NUMBER DATA

4KYFA26100E

A953123456

See the Parts Manual for parts identification numbers and required quantities and for exploded views of the genset subassemblies. Genuine Onan replacement parts are recommended for best results.

When contacting Onan for parts, service or product information, be ready to provide the model number and the serial number, both of which appear on the genset nameplate (Figure 1-1). Each character of these numbers is significant (Figures 1-2 and 1-3 on Page 1-2).

MicroLite is a trademark of the Onan Corporation.

SN5304U1G2RA 304 cc

FIGURE 1-1. TYPICAL NAMEPLATE

1-1

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Model Number Identification

Serial Number Identification

Figure 1-2 shows a breakdown of the model number for a typical genset.

MODEL NO.

4 KY FA 26100 E

1 2 3 4 5 6

1. Power capacity in kilowatts - (4000 watts)

2. Product family designation.

3. Starting method - (Remote startable)

4. Voltage and frequency code - (120 volt, 60-Hz )

5. Specification number - (Code for options and special features)

6. Specification letter - (Used to identify major design or manufacturing changes)

FIGURE 1-2. MODEL NUMBER IDENTIFICATION

Figure 1-3 shows a breakdown of the serial number for a typical genset.

SERIAL NO.

D 95 3 123456

1 2 3 4

1. Month genset was built: A = January B = February etc.

2. Year genset was built: 94 = 1994 95 = 1995 etc.

3. Location where genset was built: 0 = Fridley, Minnesota 3 = Huntsville, Alabama

4. Active serial number

FIGURE 1-3. SERIAL NUMBER IDENTIFICATION

1-2

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2. Specifications

GASOLINE MODELS LPG MODELS

4.0 KY 3.6 KY 3.6 KY 3.3 KY

GENERATOR: 2-Pole Revolving Field, Self-Excited, Electronically Regulated, 1-Phase

Power 4000 watts 3600 watts 3600 watts 3300 watts

Frequency 60 Hertz 50 Hertz 60 Hertz 50 Hertz

Voltage 100/120 volts 100/220/230 volts 100/120 volts 100/220/230 volts

Current 40/33.3 amperes

Speed 3600 rpm 3000 rpm 3600 rpm 3000 rpm

FUEL CONSUMPTION: Gasoline LPG

No load Half load Full load

ENGINE: 1-Cylinder, 4-Cycle, Spark-Ignited, OHV, Air Cooled

Bore 3.11 inch (79 mm) 3.11 inch (79 mm)

Stroke 2.44 inch (62 mm) 2.44 inch (62 mm)

Displacement 18.5 inch3 (304 cc) 18.5 inch3 (304 cc)

Compression Ratio 8.5 : 1 8.5 : 1

Oil Capacity (Beginning Spec B)* 1.6 quart (1.5 l) 1.6 quart (1.5 l)

Oil Capacity (Spec A)* 1.7 quart (1.6 l) 1.7 quart (1.6 l)

Intake Valve Clearance (Cold) 0.002 inch (0.05 mm) 0.002 inch (0.05 mm)

Exhaust Valve Clearance (Cold) 0.002 inch (0.05 mm) 0.002 inch (0.05 mm)

Spark Plug Gap 0.025 inch (0.64 mm) 0.020 inch (0.51 mm)

Spark Plug Tightening Torque 13 lbs-ft (17 N-m) 13 lbs-ft (17 N-m)

Ignition Timing (magneto type ignition)

LPG Vapor Supply Pressure (Range)

DC SYSTEM:

Nominal Battery Voltage 12 volts 12 volts

Minimum Battery Cold Cranking Capacity: Above/Below Freezing

Control Fuse 5 amperes 5 amperes

Maximum Regulated-Voltage Battery Charging Current

* –See

Periodic Maintenance

in the Operator’s Manual for oil filling instructions.

0.29 gph (1.1 l/h)

0.48 gph (1.8 l/h)

0.71 gph (2.7 l/h)

25° BTDC, non-adjustable 25° BTDC, non-adjustable

360/450 amperes 360/450 amperes

– 10 amperes – 10 amperes

36/16.4/15.7

amperes

0.21 gph (0.8 l/h)

0.37 gph (1.4 l/h)

0.58 gph (2.2 l/h)

–

36/30 amperes

1.5 lbs/h (0.7 kg/h)

2.4 lbs/h (1.1 kg/h)

3.1 lbs/h (1.4 kg/h)

9 to 13 inch (229 to 330 mm)

W.C. (water column)

33/15.0/14.3

amperes

1.1 lbs/h (0.5 kg/h)

2.2 lbs/h (1.0 kg/h)

2.9 lbs/h (1.3 kg/h)

2-1

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2-2

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3. Dimensions and Clearances

All clearances are at 70° F (21° C) room temperature. All measurements are listed in inches with millimeter measurements in parentheses. Measurements are for standard size parts.

FACTORY SPECIFICATION ALLOWABLE

DESCRIPTION MIN. MAX. LIMIT

Cylinder Head

Cylinder Head Distortion – – 0.0157

– – (0.4)

Cylinder Block

Cylinder Bore I.D. 3.1102 3.1110 3.1138

(79.00) (79.02) (79.09)

Crankshaft

Connecting Rod Journal O.D. 1.3177 1.3181 1.3157

(33.47) (33.48) (33.42)

Side Clearance – – 0.0098

– – (0.25)

Connecting Rod

Piston Pin Bore I.D. 0.7093 0.7096 0.7106

(18.015) (18.025) (18.050)

Large Bore I.D. 1.3189 1.3199 1.3204

(33.500) (33.525) (33.540)

Large Bore Clearance 0.0008 0.0022 0.0047

(0.020) (0.055) (0.120)

Side Clearance on Crankshaft 0.0157 0.0433 0.0590 (0.40) (1.10) (1.5)

Camshaft

Lobe Height (Intake and Exhaust) 1.4035 1.4059 1.3997

(35.65) (35.71) (35.55)

Piston

Piston Skirt O.D. 3.1089 3.1094 3.1063 (78.965) (78.98) (78.90)

Pin Bore I.D. 0.7084 0.7087 0.7084/0.7087

(17.994) (18.002) (17.994/18.002)

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All clearances are at 70° F (21° C) room temperature. All measurements are listed in inches with millimeter measurements in parentheses. Measurements are for standard size parts.

FACTORY SPECIFICATION ALLOWABLE

DESCRIPTION MIN. MAX. LIMIT

Piston Pin

Piston Pin O.D. 0.7087 0.7089 0.7067 (Between Pin Bosses) (18.000) (18.005) (17.95)

Piston Rings

Top Compression Ring 0.0579 0.0587 0.0563 Thickness (1.47) (1.49) (1.43)

Second Compression Ring 0.0579 0.0587 0.0570 Thickness (1.47) (1.49) (1.45)

Top Compression Ring to Ring 0.0016 0.0032 0.0047 Groove Clearancce (0.04) (0.08) (0.12)

Second Compression Ring to 0.0008 0.0012 0.0039 Ring Groove Clearance (0.02) (0.06) (0.10)

Top Compression Ring End Gap 0.0120 0.0140 0.0197

(0.305) (0.356) (0.50)

Second Compression Ring End 0.0120 0.0140 0.0197 Gap (0.305) (0.356) (0.50)

Oil Ring Side Rail Gap 0.0120 0.0140 0.0197

(0.305) (0.356) (0.50)

Intake Valve

Valve Stem O.D. 0.2740 0.2746 0.2732

(6.960) (6.975) (6.940)

Valve Guide I.D. 0.2756 0.2762 0.2768

(7.000) (7.015) (7.03)

Valve Stem to Guide Clearance 0.0010 0.0022 0.0002/0.0035

(0.025) (0.055) (0.005/0.09)

Valve Stem to Rocker Arm 0.0008 0.0032 0.0008/0.0032 Clearance (Valve Lash) (0.02) (0.08) (0.02/0.08)

Face Angle 45° N/A

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All clearances are at 70° F (21° C) room temperature. All measurements are listed in inches with millimeter measurements in parentheses. Measurements are for standard size parts.

FACTORY SPECIFICATION ALLOWABLE

DESCRIPTION MIN. MAX. LIMIT

Intake Valve Seat

Seat Width 0.0433 N/A

(1.1)

Seat Angle 45° N/A

Exhaust Valve

Valve Stem O.D. 0.2732 0.2740 0.2732

(6.940) (6.960) (6.940)

Valve Guide I.D. 0.2756 0.2762 0.2748/0.2768

(7.000) (7.015) (6.98/7.03)

Valve Stem to Guide Clearance 0.0016 0.0030 0.0002/0.0035

(0.04) (0.075) (0.005/0.090)

Valve Stem to Rocker Arm 0.0008 0.0032 0.0008/0.0032 Clearance (Valve Lash) (0.02) (0.08) (0.02/0.08)

Face Angle 45° N/A

Exhaust Valve Seat

Seat Width 0.0433 N/A

(1.1)

Seat Angle 45° N/A

Valve Springs

Free Length 1.8031 1.8228 1.6850

(45.8) (46.3) (42.8)

Distortion (Square) 0.0059

(1.5)

Ignition System Gasoline LPG

Spark Plug Gap 0.025 0.020 0.031/0.043

(0.63) (0.51) (0.8/1.1)

Ignition Timing (BTDC) 25° Not Adjustable

3-3

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3-4

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4. Torque Specifications

Mounting screws and nuts must be tightened to the specified torque settings listed in the following tables. All threads must be clean and lubricated with new engine oil before tightening. The cylinder head mounting bolts must be tightened in the proper sequence, refer to Section

10. Engine Block Assembl

torques are not specified, tighten the screws and nuts according to Tables 4-3 and 4-4 on Page 4-2. The grade numbers are indicated on top of the screw or bolt head.

TABLE 4-1. ENGINE TORQUE SPECIFICATIONS

ITEM POUND - FEET NEWTON - METERS

Air Deflector Bolts 8 - 15 11 - 22

Connecting Rod Bolts 18 -20 24 - 27

Cylinder Head Bolts (Cold)

#1 and #6 12 - 16 16 - 22

#2 thru #5 31 - 37 42 - 50

Cylinder Air Housing Bolts

M6 X 12 5 - 8 7 - 11

y. When tightening

M8 X 10, M8 X 16 8 - 15 11 - 20

Gearcase Cover 12 - 16 16 - 22

Governor Lever Bolt 7 12

Intake Elbow Screws 8 - 12 11 - 16

Muffler to Engine (Spec A) 12 - 16 16 - 22

Muffler to Eng. (Begin Spec B) 8 - 11 11 - 15

Muffler to Base (Begin Spec B) 25 lb-in. 3

Oil Base Bolts 10 - 14 14 - 19

Oil Drain Screw 5 - 8 7 - 11

Rocker Arm Adjustment Nut 5 - 8 7 - 11

Spark Plug 7 - 18 10 - 24

Valve Cover 5 - 8 7 - 11

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TABLE 4-2. GENERATOR TORQUE SPECIFICATIONS

ITEM POUND - FEET NEWTON - METERS

Rotor Through-Bolt 40-50 54-68

Stator Through-bolt 5-8 7-11

Endbell to Stator Housing 5-8 7-11

Mount Assy. Bolt (Spec A) 38-43 52-58

Mount Assy. Bolt (Begin Spec B) 35-40 47-53

Stator Housing to Engine Block 15-18 21-24

TABLE 4-3. METRIC BOLT TORQUE SPECIFICATIONS - NO GRADE OR 8.8 GRADE

SIZE POUND - FEET NEWTON - METERS

M6 6 - 7 8 - 9

M8 13 - 15 18 - 21

M10 29 - 33 39 - 45

M12 46 - 54 63 - 73

TABLE 4-4. METRIC BOLT TORQUE SPECIFICATIONS - 10.9 GRADE

SIZE POUND - FEET NEWTON - METERS

M6 7 - 8 10 - 11

M8 17 - 20 24 - 27

M10 35 - 41 48 - 56

M12 57 - 67 77 - 90

4-2

Page 16

5. Preparing for Service

TROUBLESHOOTING

Refer to through the appropriate subsections before starting work on the genset. It has the following subsections:

• Control System

• Generator

• Primary Systems

The subsections list typical problems along with possible causes and corrective actions. Note that some problems might have several possible causes. It may be necessary to investigate several possible causes in order to isolate the actual source of the problem.

Section 6. Troubleshooting

and work

SPECIAL TOOLS

The following special tools are required to service the genset. See the Onan Tool Catalog.

Engine Tools

Torque wrench (0-75 lbs-ft or 0-100 N-m) Feeler gauge Leak Down Tester Spark plug gap gauge Cylinder compression tester Flywheel puller Snap ring pliers Cylinder ridge reamer Piston ring compressor Piston ring spreader Cylinder hone Valve seat cutter Valve spring compressor Piston groove cleaner Outside micrometer set (0 to 4 in.) Telescoping gauge set (1/2 in. to 6 in.) Hole gauge (0.300 in. to 0.400 in.) Plasti-Gage bearing clearance guide

Generator Tools

Lead or dead-blow hammer Steel rod (.45 inch dia. x 7.875 inch long)

Battery hydrometer VOM multi-tester Frequency meter Armature growler Load test panel Jumper wires

SAFETY CONSIDERATIONS

Always consider the safety aspects of any service procedure. Servicing gensets presents several hazards that the service technician must be aware of to safely complete the job. Study the safety precautions at the beginning of this manual and familiarize yourself with the hazards listed in Table 5-1 on Page 5-2. Approach the job in a safety-conscious manner. Being safety conscious is the most effective way to avoid injury to yourself and to others. Reduce the risk of an accident by adopting the following safeguards.

Safeguards to Avoid Hazards

Use personal protection:

wearing the appropriate safety equipment such as:

• Safety shoes

• Gloves

• Safety glasses

• Hard hats

• Ear plugs

Do not wear rings, jewelry or loose clothing: these can get caught on equipment, or conduct electricity.

Reduce the hazard:

well-maintained equipment reduce the risk of hazard. Leave all guards and shields in place on machinery, and maintain equipment in top condition. Store flammable liquids in approved containers, away from fire, flame, spark, pilot light, arc-producing equipment and other ignition sources. Keep the work area clean, well-lighted, and well-ventilated. Keep fire extinguishers and safety equipment nearby, and be prepared for any emergency.

Protect your body by

A safe, orderly work area and

5-1

Page 17

TABLE 5-1. HAZARDS AND THEIR SOURCES

• Fire and explosions

Leaking or spilled fuel Hydrogen gas from charging battery Oily rags improperly stored Flammable liquids improperly stored Any fire, flame, spark, pilot light, arcproducing equipment or other ignition sources

• Burns

Hot exhaust pipes Hot engine and generator surfaces Hot engine oil Electrical short in DC wiring system

• Poisonous gases

Carbon monoxide from faulty exhaust Operating genset where exhaust gases can accumulate

Develop safe work habits:

the cause of most accidents involving tools or machinery. Be familiar with your tools and machines and learn how to use them safely. Use the right tool for the job, and check its condition before starting. Follow all warnings and cautions in this manual, and take extra precautions when working around electrical equipment. Avoid working alone, and do not take risks. Do not work when tired or after consuming any alcohol or drug that makes the operation of equipment unsafe.

Be prepared for a potential accident:

Cross and public safety departments offer courses in first aid, CPR, and fire control. Use this information to be ready for an accident. Be safety-conscious, and make safety procedures part of the work routine.

Unsafe practices are

The Red

• Electrical shock (AC)

Improper genset load connections Faulty RV wiring Faulty electrical appliance Faulty genset wiring Working in damp conditions Jewelry touching electrical components

• Rotating Machinery

Jewelry or loose clothing catching in moving parts

• Slippery Surfaces

Leaking or spilled oil

• Heavy Objects

Removing genset from vehicle Removing heavy components

In a compartment mount installation, a special compartment is built into the coach to house the genset (Figure 5-1 on Page 5-3). The compartment is constructed with a vapor-tight barrier that seals off the genset from the coach interior. The genset is usually mounted to the floor of the compartment. Access to the compartment is through a door located in the exterior of the coach.

The under-floor-mount installation uses special brackets to suspend the genset under the floor of the coach. The mounting brackets bolt to support members that are built into the vehicle framework (Figure 5-2). The genset is mounted near the exterior of the vehicle. Access is provided through a door located in the exterior of the coach.

SET REMOVAL GUIDELINES

Some service procedures will require removing the genset from the coach. While there are many variations, genset installations are generally classified as either conventional compartment mount or under-the-floor mount.

Due to the wide variety of coach designs, it is not possible to specify the exact removal procedures for each type of installation. If, after examining the following sections, a satisfactory method for removing the set cannot be determined, contact the coach manufacturer or set installer to obtain their recommendations before attempting set removal.

5-2

Page 18

BATTERY POSITIVE (+)

AND REMOTE CONTROL

HARNESS OPENING

METAL

BARRIER

DOOR

MOUNTING

HOLES

FUEL LINE

CONNECTION

AC CONDUIT

CONNECTION

BATTERY NEGATIVE (-) CONNECTION

FIGURE 5-1. TYPICAL COMPARTMENT MOUNT INSTALLATION (SPEC A SHOWN)

DOOR

COACH

FLOOR

FUEL LINE

CONNEC

TION

METAL BARRIER REQUIRED

IF INSTALLED BELOW A

WOODEN FLOOR

SIDE

PANELS

MOUNTING HOLES

SPEC A (4)

BEGIN SPEC B (6)

M1723-1s

AC CONDUIT

CONNEC

TION

BATTERY NEGATIVE (-) CONNECTION

BATTERY POSITIVE (+)

AND REMOTE CONTROL

HARNESS OPENING

BOTTOM

RAIL

FIGURE 5-2. TYPICAL UNDER-FLOOR MOUNT INSTALLATION (BEGIN SPEC B SHOWN)

5-3

M2001s

Page 19

Disconnecting Set from Vehicle Systems

Disconnect the following items from the genset. Refer to Figures 5-1 and 5-2 on Page 5-3 for component locations in typical genset installations.

Some installations may require partial removal of the set to gain access to the battery cable, fuel line and other connections. Read this section before starting set removal.

1. Disconnect the vehicle negative (–) battery cable at the battery terminal.

WARNING

Sparks and high current could cause fire and other damage to the battery, battery cables and vehicle if the loose ends of cables connected to the battery touch. Always disconnect the negative (–) battery cable from the battery before disconnecting the battery cables from the genset.

2. Remove the genset negative (–) battery cable at the battery terminal.

3. Disconnect the genset positive (+) battery cable from the B+ connection on the genset.

4. Disconnect the remote control wire connector from the left side of the genset housing.

5. Disconnect the generator load wires from inside the genset. Remove the control assembly mounting bracket (Figure 6-1 on Page 6-2 or Figure 6-2 on Page 6-3). Raise the control assembly and disconnect the ground and neutral (L2) lead from the ground terminal. Disconnect the inline load (L1) lead connection. Tag the wires for identification when reconnecting.

6. Loosen the conduit connector elbow, and pull the load wires and flexible conduit free of the genset.

7. Disconnect the exhaust tail pipe from the genset. Disconnect any exhaust support brackets or hangers that restrict removal of the genset.

8. Disconnect the fuel line from the genset. Follow the applicable instructions depending on the fuel.

Gasoline-fueled Gensets:

the fuel line from the genset and securely

Disconnect

plug the end of the fuel line to prevent leakage or an accumulation of explosive gasoline vapor.

LPG-fueled Gensets:

off valve(s) at the LPG container(s) and move the vehicle outside and away from below-grade spaces where LPG could accumulate. To purge most of the LPG from the fuel line and genset, run the genset (if it starts) until it runs out of fuel (LPG container valve closed). To purge some of the remaining LPG, press the regulator primer plunger (Figures 8-18 and 8-19 on Pages 8-22 and 8-23) while cranking the engine for 10 seconds. Disconnect the fuel line from the genset and plug the end of the hose to prevent fuel from escaping if someone inadvertently opens the shutoff valve(s) at the LPG container(s).

WARNING

Gasoline and LPG (liqui-

Close the fuel shut-

fied petroleum gas) are flammable and explosive and can cause severe personal injury or death. Do not smoke. Keep flames, sparks, pilot lights, arcproducing and switching equipment, and all other sources of ignition away from fuel tank and system, and areas sharing ventilation. Have an ABC fire extinguisher handy.

WARNING

LPG is flammable and explosive and can cause asphyxiation. NFPA 58, Section 1.6 requires all persons handling LPG to be trained in proper handling and operating procedures.

LPG “sinks” and can accumulate in explosive concentrations. Before disconnecting the LPG fuel line, close the fuel shutoff valve(s) at the LPG container(s) and move the vehicle outside and away from pits, basements, and other belowgrade spaces where LPG could accumulate.

5-4

Page 20

Set Removal

After the genset is disconnected from electrical, exhaust and fuel systems, examine the set mounting and support system. Locate all mounting bolts and support members for the set. In most installations the generator housing will be mounted to the coach framework. Depending on the installation, the set may be removable from the side, back or bottom.

Verify that the genset is adequately supported before loosening any of the mounting bolts or support members. Use a forklift to lift or move the set.

WARNING

The genset is heavy, and can cause severe personal injury if dropped during removal. Use the recommended removal procedures, and keep hands and feet clear while removing mounting bolts. Make certain that all vehicle systems have been disconnected before performing this procedure.

Park the vehicle on a level surface which can support the forklift. Move the transmission to PARK, lock the brakes and remove the ignition key. Do not move the vehicle during this procedure.

WARNING

Dropping the genset can cause severe personal injury or death. Make sure no one moves the vehicle during this procedure and that the procedure is performed very carefully and only as instructed.

Compartment Mount:

1. Use a forklift to support and move the genset.

2. Make sure that the genset is adequately supported before removing any of the mounting bolts.

3. Remove all mounting bolts then slide the genset out of the compartment and onto the forklift. Slowly lower the genset before moving it to the service area.

5-5

Page 21

Under-Floor Mount:

1. Use a forklift to support the genset at the points shown in Figure 5-3.

2. Raise the lift so it contacts the bottom of the genset housing, then place slight upward pressure on the set. Make certain that the genset is fully supported by the lift before continuing.

3. Loosen bolts between genset base pan and side mounting panels (loosen bolts about six turns).

4. Loosen bolts securing the side panels to the rear panel (note slotted holes) or braces and pull side panels away from genset. Retighten side panels to back panel bolts.

5. Remove side and rear panel to genset base mounting bolts. Slowly lower the genset until it clears all obstructions and can be safely moved out from under the vehicle.

When reinstalling the genset, be sure that all bolts, brackets, and electrical, exhaust, and fuel system components are connected exactly as they were before removal.

FORKLIFT

FIGURE 5-3. COMPLETE GENSET REMOVAL (SPEC A SHOWN)

5-6

Page 22

6. Troubleshooting

INTRODUCTION

Use the following troubleshooting guide to help diagnose genset problems. The troubleshooting section is divided into four parts:

• Control – Spec A models (page 6-4)

• Control – Begin Spec B models (page 6-16)

• Generator – All specs Page 6-28)

• Engine Primary Systems – All Specs (page

6-32)

Common problems are listed with their possible causes. Refer to the Corrective Action column for the appropriate test or adjustment procedure. The section and page number in the right column lists

the location of the test or adjustment procedure in this manual.

Refer to Figures 6-1 and 6-2 on Pages 6-2 and 6-3 to identify the component locations for the Spec A and Spec B models.

Conditional schematics are used to highlight the circuitry that is energized during the sequence of events. These conditional schematics are for a typical gasoline fueled genset. Always refer to the wiring schematic and diagram in Section

Diagram/Schematic

and spec of the genset when troubleshooting.

Make a thorough inspection of the genset wiring to make sure that good wire harness and ground connections are made. Correct wiring problems before performing tests or replacing any components.

that corresponds to the model

12. Wiring

6-1

Page 23

STARTER MOTOR B1

STATOR CONNECTOR P5

IGNITION COIL T1

STATOR CONNECTOR P6

BRUSH BLOCK

MAGNETO IGNITION G2

VOLTAGE REGULATOR VR1

START RELAY K1

FUEL PUMP E2

(FUEL SHUTOFF

SOLENOID ON LPG MODELS)

REMOTE CONTROL

CONNECTOR

BATTERY CHARGE

RESISTOR R1

BRIDGE RECTIFIER CR1

START/STOP SWITCH S1

FUSE F1

CIRCUIT BREAKER CB1

SPARK PLUG E1

P4 CONNECTOR

J4 CONNECTOR

P1 CONNECTOR

J1 CONNECTOR

CONTROL ASSEMBLY A1

FIGURE 6-1. COMPONENT LOCATIONS – GASOLINE-FUELED SPEC A MODELS

6-2

ES2017s

Page 24

STARTER MOTOR B1

TRANSFORMER T1

(50 HERTZ ONLY)

BRUSH BLOCK

MAGNETO IGNITION G2

STATOR CONNECTOR P5

STATOR CONNECTOR P6

50 HZ MODELS HAVE BATTERY CHARGER

(VR2) MOUNTED INSIDE THE HOUSING

(NOT SHOWN - SEE FIGURE 77)

FUEL SHUTOFF

SOLENOID E3

FUSE F1

START/STOP SWITCH S1

IGNITION COIL T1

VOLTAGE REGULATOR VR1

FUEL PUMP E2

(FUEL SHUTOFF

SOLENOID ON

LPG MODELS)

REMOTE CONTROL

CONNECTOR

CIRCUIT BREAKER CB1

START RELAY K1

CONTROL ASSEMBLY A1

SPARK PLUG E1

FIGURE 6-2. COMPONENT LOCATIONS – GASOLINE-FUELED MODELS, BEGINNING WITH SPEC B

ES2017s

6-3

Page 25

Spec A Start - Cranking Mode

Battery positive (B+) is supplied to the control assembly (A1) through control fuse (F1). Holding the Start/Stop switch (S1) in the Start position activates control assembly (A1) by closing the start signal input circuit. While the Start/Stop switch is held, the control assembly supplies the following outputs:

• Battery positive (B+) is supplied to the start relay coil (K1). This energizes the start relay. The start relay con-

tacts close supplying battery positive (B+) to the starter motor B1. The starter begins to crank the engine to initiate starting.

BATTERY BT1

FUSE F1

START/STOP SWITCH S1

START

STARTER MOTOR B1

RELAY K1

CONTROL ASSEMBLY A1

J1 CONNECTOR

P1 CONNECTOR

FIGURE 6-3. SPEC A START – CRANKING MODE

6-4

Page 26

WARNING

Many troubleshooting procedures present hazards that can result in severe personal injury or death. Only qualified service personnel with knowledge of fuels, electricity, and machinery hazards should perform service procedures. Review safety precautions on page iii.

TABLE 6-1. SPEC A CONTROL TROUBLESHOOTING – CRANKING MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Does 1. Open control fuse F1. 1. Check fuse. If open, locate and correct Not Crank cause of overload. Replace fuse.

2. Insufficient cranking voltage due to: 2a. Check condition of battery and (Also see Table 6-5 on page 6-13) recharge or replace. a. Battery not charged. 2b. Clean and tighten all connections at b. Battery connections loose or dirty. battery, K1 start solenoid, and starter c. Battery cable size too small. motor.

2c. Increase starting battery cable size.

3. Start solenoid (K1) not energized 3a. Check wiring continuity to the start due to: solenoid (K1) coil from control assy. a. Open circuit to start solenoid coil. (A1) and from ground to start solenoid. b. Defective start solenoid coil. 3b. Test start solenoid (K1). 7-6 c. Defective Start/Stop switch. 3c. Test Start/Stop switch (S1). 7-5 d. Defective control assembly (A1). 3d. Measure voltage between start solenoid 7-6

terminal I and ground with switch (S1) held in the Start position. If voltage is not present and continuity and battery check OK, Cont. assy. (A1) is defective.

4. Starter (B1) not energized due to: 4a. Check continuity between starter lead on 7-6 a. Open circuit to starter (B1). start solenoid (S) and gnd. (4 ±1 ohm). b. Open circuit between battery (B+) 4b. Check wiring continuity between battery 7-6

and the start solenoid contact (BAT). (B+) and the start solenoid (BAT). c. Defective start solenoid (K1) . 4c. Measure voltage between starter terminal 7-6 d. Defective starter (B1). and ground with switch (S1) held in the

Start position. If voltage is not present and continuity checks OK, start solenoid (K1) is defective.

4d. If voltage is present in step 4c, starter 8-26

is defective.

5. If engine cranks from set but not from 5a. Check wiring continuity between remote control panel, fault is due to: control assembly (A1) and remote a. Open circuit between control assy. Start/Stop switch.

(A1) and remote Start/Stop switch.

b. Remote Start/Stop switch faulty. 5b. Test remote Start/Stop switch.

6-5

Page 27

Spec A Start - Ignition Mode

Holding the Start/Stop switch (S1) in the Start position activates the following ignition circuit:

• Control assembly (A1) enables the ignition circuit to open a ground path through the control assembly to the

magneto assembly (G2) so that output from the magneto will energize the ignition coil (T1).

• With the engine cranking, a permanent magnet in the flywheel rotates, at the proper time, past the magneto

to induce a voltage at the ignition coil (T1) that fires the spark plug (E1) for ignition.

• Battery positive (B+) is supplied to the fuel pump (E2) or fuel shutoff solenoid (E2) and regulator(K2) on LPG

models. (Schematic for gasoline fueled model shown.)

BATTERY BT1

START/STOP SWITCH S1

CONTROL ASSEMBLY A1

J1 CONNECTOR

STARTER MOTOR B1

P1 CONNECTOR

MAGNETO

IGNITION G2

FUSE F1

START

RELAY K1

OIL LEVEL

SWITCH S2

FUEL PUMP E2 (FUEL SHUTOFF

SOLENOID ON LPG MODEL)

SPARK PLUG E1

IGNITION

COIL T1

FIGURE 6-4. SPEC A START – IGNITION MODE

6-6

ES2017-1s

Page 28

WARNING

TABLE 6-2. SPEC A CONTROL TROUBLESHOOTING – IGNITION MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Cranks 1. Restricted fuel supply due to: 1a. Add fuel if tank is low. But Does Not a. Fuel level below pickup tube in tank. 1b. Open fuel supply valve (if equipped). Start b. Fuel line supply valve closed. 1c. Replace clogged fuel filter and check 8-19

c. Fuel filter clogged. fuel supply for contamination.

2. Faulty ignition due to worn or fouled 2. Refer to spark plug, faulty plug wire, faulty and service procedures. ignition coil or magneto.

3. Sticking choke or carburetor mixture 3. Refer to screws incorrectly adjusted. adjustments.

4. Fuel pump (E2) not working due to: 4a. Measure voltage between fuel pump 8-19 a. Fuel pump defective. connector and ground with the engine b. Open circuit between fuel pump and cranking. If B+ voltage is not present,

control assembly (A1) or control proceed to 4b. If voltage is present, assembly is defective. (min. 6 VDC) fuel pump is defective.

4b. Check continuity between control 8-19

assembly and fuel pump. If connections are good and voltage was not measured in 4a, replace control assembly (A1).

5. Faulty fuel solenoid, priming solenoid, 5. Refer to or regulator on LPG models. for service procedures.

6. Governor linkage stuck or binding. 6. Check governor arm movement. 8-9

See

7. Oil level switch (S2) closed due to: 7a. Check oil level and add oil if low. a. Low oil level. 7b. Check low oil level switch. 10-2 b. Defective low oil level switch.

Ignition System

Gasoline Fuel System

LPG Fuel System

Governor

section.

for test 8-6

for 8-11

8-22

6-7

Page 29

Spec A Start - Field Flash Mode

Holding the Start/Stop switch (S1) in the Start position activates the following field flash circuit:

• Battery positive (B+) is supplied to the control assembly (A1) and the voltage regulator (VR1) at pin 7. From

pins 9 and 10 of the voltage regulator, excitation voltage is sensed through the brushes to the rotor field winding.

• The excitation voltage flashes the generator field winding to ensure that there is adequate magnetism to induce

generator voltage buildup.

START/STOP SWITCH S1

BATTERY BT1

CONTROL ASSEMBLY A1

FUSE F1

J1 CONNECTOR

P1 CONNECTOR

P4 CONNECTOR

BRUSH BLOCK

J4 CONNECTOR

FIGURE 6-5. SPEC A START – FIELD FLASH MODE

6-8

VOLTAGE REGULATOR VR1

ES2017-2s

Page 30

WARNING

TABLE 6-3. SPEC A CONTROL TROUBLESHOOTING – FIELD FLASH MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Starts 1. Low oil level. 1. Check oil level and add oil if low. But Stops 2. Defective low oil level switch. 2. Disconnect low oil level switch and 10-2 When Start check set operation. Replace if defective. Switch Is 3. No field flash voltage due to: 3a. Check wiring continuity to the brush 9-8 Released a. Open circuit in wiring. block F1-F2, voltage regulator VR1,

b. Brushes not making good contact control assembly A1 and generator

with slip rings. B1-B2 and Q1-Q2 windings. Check

c. Slip ring surface is rough or pitted. connections of P5 and P6 connectors

on the generator housing.

3b. Check brushes for wear and for contact 9-12

with the slip rings.

3c. Check slip rings

4. Defective generator, control assembly 4. Perform field voltage test. 9-8 A1, or voltage regulator VR1.

6-9

Page 31

Spec A Run Mode

When the engine starts, release the Start/Stop switch and it will return to the center Run position. The following events occur:

• Control assembly (A1) opens the circuit to the start solenoid (K1), which opens the circuit to the starter motor

(M1) to stop cranking. Control assembly (A1) also opens the field flash circuit to AVR pin 7.

• Voltage from the battery, used to power the control assembly (A1) and the fuel pump (E2), is replaced with output

voltage from the generator charge winding B1-B2. (Refer to assembly senses this output for the start disconnect function.

Battery Charge Mode

on page 6-12.) The control

• Remote run output is energized through the control assembly (A1) to power the time meter, battery condition

meter and run lamp in the optional remote control.

• Voltage from the generator Q1-Q2 winding provides power to the voltage regulator VR1 to use for supplying field

current to the generator. (Refer to

CONTROL ASSEMBLY A1

Generator AC Output Mode

START/STOP SWITCH S1

on page 6-29.)

BATTERY BT1

FUSE F1

J1 CONNECTOR

FUEL PUMP E2

P1 CONNECTOR

MAGNETO

IGNITION G2

IGNITION

COIL T1

FIGURE 6-6. SPEC A RUN MODE

6-10

SPARK PLUG E1

ES2017-3s

Page 32

WARNING

TABLE 6-4. SPEC A CONTROL TROUBLESHOOTING – RUN MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Starts 1. Fuel level is below genset fuel 1. Check fuel and oil level and refill if low. and Runs, pickup tube or oil level is low. 2. Refer to choke section for adjustments. 8-17 Then Stops. 2. Faulty choke operation. 3. Remove any objects or debris that may Set Restarts 3. Vapor lock from high ambient restrict airflow. Make sure fuel system Immediately temperature. is installed correctly. or After Cool 4. Contaminated or incorrect fuel. 4. Refill tank with fresh fuel. Down.

Remote 1. Open circuit in remote control wiring. 1. Check continuity between remote Control control and control assembly (A1). Run Lamp, 2. If battery condition meter and run lamp 2. Replace time meter. Time Meter, work but time meter does not, or Battery time meter is defective. Condition Meter 3. If time meter works but battery condition 3a. Connect a voltmeter between the Inoperative meter does not operate: positive terminal on battery charge

a. Defective battery condition meter. meter and ground. Use the following to b. Defective zener diode inside remote determine fault:

control. If reading equals battery voltage

minus 10 volts, battery condition meter is defective.

3b. If reading does not equal battery

voltage minus 10 volts, zener diode is defective.

4. Meters and switch function properly but 4. Replace remote Start/Stop switch (S2). run lamp does not illuminate. Lamp (internal to switch) is burned out.

5. If remote switch functions properly for 5. Check remote running output voltage starting and stopping genset but (approximately 12 VDC) during run meters and run lamp do not operate, condition from control assembly J2-5 and step 1 checks OK, control assy. to ground and from J2-6 to ground. (A1) defective. If voltage is not present, replace control

assembly (A1). If voltage is present, check continuity

6. Too much DC load (over 2–amps) of remote control wiring. connected to the remote output. 6. Turn off the genset, disconnect the

remote control, and check for shorts or too many remote accessories.

6-11

Page 33

Spec A Battery Charge Mode

With the genset running, AC voltage is produced in the B1-B2 windings for the battery charge circuit.

• The AC output voltage from the B1-B2 winding is converted to DC voltage when it passes through the full-wave

rectifier bridge (CR1). The voltage is then supplied through battery charge resistor (R1). The 12-volt DC output (one-ampere maximum) is used to power the control assembly (A1), fuel pump (E2), the remote control, and to prevent discharge of the genset starting battery during genset operation. This output is not sufficient to charge a low or dead battery.

STATOR

BRIDGE

RECTIFIER

CR1

CONNECTORS

BATTERY BT1

FUSE F1

REMOTE CONTROL

CONTROL ASSEMBLY A1

BCEF

J1 CONNECTOR

BATTERY CHARGE

RESISTOR R1

START/STOP SWITCH S1

FUEL PUMP E2

P1 CONNECTOR

FIGURE 6-7. SPEC A BATTERY CHARGE MODE

6-12

ES2017-4s

Page 34

WARNING

TABLE 6-5. SPEC A CONTROL TROUBLESHOOTING – BATTERY CHARGE MODE

Trouble Possible Cause Corrective Action Section/

Page

Low Battery 1. Weak or discharged battery due to: 1a. Replenish electrolyte and recharge Voltage a. Low electrolyte level in battery. battery.

b. Long periods of non-use. 1b. Connect a separate battery charger to c. Improperly wired battery. bring battery up to full charge. d. Load connected to battery while set 1c. Reconnect and check battery connec-

is turned off. tion.

e. Too much DC load on genset 1d. Disconnect load and recharge

starting battery. battery.

1e. Remove other DC loads from genset

starting battery.

2. Genset charging circuit not 2a. Check all wiring connections between functioning due to: the generator B1-B2 windings and the a. Open in circuit between generator Battery B+ connection, including all

B1-B2 winding and battery (B+). connections to the diode bridge (CR1) b. Open charging resistor (R 1). and battery charge resistor (R1). c. Diode bridge (CR1) defective. 2b. Remove wires from the charge resistor 7-8 d. Generator B1–B2 defective. (R1) and measure its resistance.

A normal reading is 4 to 6 ohms. 2c. Refer to diode bridge (CR1) test. 7-8 2d. Refer to generator test section. 9-8

NOTE: The battery charging circuit is designed to maintain the genset starting battery. The charging circuit will not charge a low or bad battery. A low battery should be charged up with a battery charger.

6-13

Page 35

Spec A Stop Mode

Momentarily pushing the Start/Stop switch (S1) to the Stop position begins the stop mode with the following results:

• Control assembly (A1) de-energizes the ignition enable circuit, grounding the magneto (G2) ignition circuit to

stop the engine.

• Control assembly (A1) also opens the circuit to the fuel pump (E2) and to the remote control.

• Control assembly (A1) start disconnect senses a drop in voltage from the battery charge winding B1-B2 and

activates the remote stop latch to prevent restart during the stop mode.

STATOR

CONNECTOR

START/STOP SWITCH S1

CONTROL ASSEMBLY A1

J1 CONNECTOR

P1 CONNECTOR

MAGNETO

IGNITION G2

FIGURE 6-8. SPEC A STOP MODE

IGNITION

COIL T1

SPARK PLUG E1

6-14

Page 36

WARNING

TABLE 6-6. SPEC A CONTROL TROUBLESHOOTING – STOP MODE

Trouble Possible Cause Corrective Action Section/

Page

Genset 1. If set can be stopped from set control 1a. Check wiring continuity between Does Not Stop but not from remote control panel, control assembly (A1) and remote When Switch fault is due to: Start/Stop switch. Is Pushed To a. Open circuit between control assy. 1b. Check remote Start/Stop switch. Stop (A1) and remote Start/Stop switch.

b. Remote Start/Stop switch faulty.

Always remove the load a few 2. If genset can be stopped from remote 2a. Check wiring continuity between minutes before control but not from genset, fault due to: control assembly (A1) and Start/ stopping the a. Open circuit between control assy. Stop switch (S1). genset to allow (A1) and Start/Stop switch (S1). 2b. Check Start/Stop switch (S1). 7-5 cool down. b. Start/Stop (S1) switch faulty.

6-15

Page 37

Begin Spec B Start - Cranking Mode

• Battery positive (B+) is supplied to the start relay coil (K1). This energizes the start relay. The start relay con-

tacts close supplying battery positive (B+) to the starter motor B1. The starter begins to crank the engine to initiate starting.

BATTERY BT1

FUSE F1

START/STOP SWITCH S1

START

STARTER MOTOR B1

RELAY K1

CONTROL ASSEMBLY A1

P1 CONNECTOR

J1 CONNECTOR

FIGURE 6-9. SPEC B START – CRANKING MODE

6-16

Page 38

WARNING

TABLE 6-7. BEGIN SPEC B CONTROL TROUBLESHOOTING – CRANKING MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Does 1. Open control fuse F1. 1. Check fuse. If open, locate and correct Not Crank cause of overload. Replace fuse.

2. Insufficient cranking voltage due to: 2a. Check condition of battery and (Also see Table 6-11 on page 6-25) recharge or replace. a. Battery not charged. 2b. Clean and tighten all connections at b. Battery connections loose or dirty. battery, K1 start solenoid, and starter c. Battery cable size too small. motor.

2c. Increase starting battery cable size.

terminal I and ground with switch (S1) held in the Start position. If voltage is not present and continuity and battery check OK, Cont. assy. (A1) is defective. 7-6

4. Starter (B1) not energized due to: 4a. Check continuity between starter lead on a. Open circuit to starter (B1). start solenoid (S) and gnd. (4 ±1 ohm). b. Open circuit between battery (B+) 4b. Check wiring continuity between battery

Start position. If voltage is not present and continuity checks OK, start solenoid (K1) is defective.

4d. If voltage is present in step 4c, starter 8-26

is defective.

(A1) and remote Start/Stop switch.

b. Remote Start/Stop switch faulty. 5b. Test remote Start/Stop switch.

6-17

Page 39

Begin Spec B Start - Ignition Mode

Holding the Start/Stop switch (S1) in the Start position activates the following ignition circuit:

• Control assembly (A1) enables the ignition circuit to open a ground path through the control assembly to the

magneto assembly (G2) so that output from the magneto will energize the ignition coil (T1).

• With the engine cranking, a permanent magnet in the flywheel rotates, at the proper time, past the magneto

to induce a voltage at the ignition coil (T1) that fires the spark plug (E1) for ignition.

• Battery positive (B+) is supplied to fuel pump (E2), fuel shutoff solenoid (E3) and regulator (K2) on LPG mod-

els. (Schematic for gasoline fueled model shown.)

BATTERY BT1

START/STOP SWITCH S1

CONTROL ASSEMBLY A1

P1 CONNECTOR

STARTER MOTOR B1

J1 CONNECTOR

FUSE F1

START

RELAY K1

FUEL PUMP E2

(FUEL SHUTOFF - LPG)

FUEL SHUTOFF E3

OIL LEVEL SWITCH S2

(SPEC BF)

SPARK PLUG E1

MAGNETO

IGNITION G2

IGNITION

COIL T1

FIGURE 6-10. SPEC B START – IGNITION MODE

6-18

ES2017-1s

Page 40

WARNING

TABLE 6-8. BEGIN SPEC B CONTROL TROUBLESHOOTING – IGNITION MODE

Trouble Possible Cause Corrective Action Section/

Page

c. Fuel filter clogged. fuel supply for contamination.

2. Faulty ignition due to worn or fouled 2. Refer to spark plug, faulty plug wire, faulty and service procedures. ignition coil or magneto.

3. Sticking choke or carburetor mixture 3. Refer to screws incorrectly adjusted. adjustments.

control assembly (A1) or control proceed to 4b. If voltage is present, assembly is defective. (min. 6 VDC) fuel pump is defective.

4b. Check continuity between control

assembly and fuel pump. If connections are good and voltage was not measured in 4a, replace control assembly (A1).

5. Fuel shutoff solenoid (E3) not 5. Measure voltage at fuel shutoff sol. (E3) 8-24 energized. terminals with the engine cranking. If B+

voltage is not present, check the wiring connections and control assembly A1 output test. If voltage is present (min. 6 VDC) and engine is not receiving fuel, fuel shutoff solenoid is defective.

6. Faulty fuel solenoid, priming solenoid, 6. Refer to or regulator on LPG models. for service procedures.

Ignition System

for test 8-6

Gasoline Fuel System

LPG Fuel System

for 8-11

8-22

7. Governor linkage stuck or binding. 7. Check governor arm movement. 8-9

See

Governor

8. Oil level switch (S2) (Spec B-F, if 8a. Check oil level and add oil if low. applicable) closed due to: a. Low oil level. 8b. Check low oil level switch. 10-2 b. Defective low oil level switch.

section.

6-19

Page 41

Begin Spec B Start - Field Flash Mode

Holding the Start/Stop switch (S1) in the Start position activates the following field flash circuit:

• Battery positive (B+) is supplied to the control assembly (A1) and the voltage regulator (VR1) at pin 7. From

pins 9 and 10 of the voltage regulator, excitation voltage is sensed through the brushes at the rotor field winding.

• The excitation voltage flashes the generator field winding to ensure that there is adequate magnetism to induce

generator voltage buildup.

START/STOP SWITCH S1

BATTERY BT1

CONTROL ASSEMBLY A1

FUSE F1

P1 CONNECTOR

BRUSH BLOCK

FIGURE 6-11. SPEC B START – FIELD FLASH MODE

J1 CONNECTOR

VOLTAGE REGULATOR VR1

P4 CONNECTOR

J4 CONNECTOR

ES2017-2s

6-20

Page 42

WARNING

TABLE 6-9. BEGIN SPEC B CONTROL TROUBLESHOOTING – FIELD FLASH MODE

Trouble Possible Cause Corrective Action Section/

Page

Engine Starts 1. Low oil level. 1. Check oil level and add oil if low. But Stops 2. Defective low oil level switch 2. Disconnect low oil level switch and 10-2 When Start (Spec B-F, if applicable). check set operation. Replace if defective. Switch Is 3. No field flash voltage due to: 3a. Check wiring continuity to the brush 9-8 Released a. Open circuit in wiring. block F1-F2, voltage regulator VR1,

b. Brushes not making good contact control assembly A1 and generator

with slip rings. B1-B2 (50 Hz) and Q1-Q2 windings.

c. Slip ring surface is rough or pitted. Check connections of P5 and P6

connectors on the generator housing.

3b. Check brushes for wear and for contact 9-12

with the slip rings.

3c. Check the slip rings.

4. Defective generator, control assembly 4. Perform field voltage test. 9-8 A1, or voltage regulator VR1.

6-21

Page 43

Begin Spec B Run Mode

When the engine starts, release the Start/Stop switch and it will return to the center Run position. The following events occur:

• Control assembly (A1) opens the circuit to the start solenoid (K1), which opens the circuit to the starter motor

(M1) to stop cranking. Control assembly (A1) also opens the field flash circuit to AVR pin 7.

• 50 Hz models only: Voltage from the battery, used to power the control assembly (A1) and the fuel pump (E2),

is replaced with output voltage from the generator charge winding B1-B2. (Refer to page 6-24.)

Battery Charge Mode

• The control assembly senses output voltage from L1 (X1 50-Hertz) for the start disconnect function.

• Remote run output is energized through the control assembly (A1) to power the time meter, battery condition

meter and run lamp in the optional remote control .

• Voltage from the generator Q1-Q2 winding provides power to the voltage regulator VR1 to use for supplying field

current to the generator. (Refer to

START/STOP SWITCH S1

Generator AC Output Mode

on page 6-30.)

BATTERY BT1

FUSE F1

CONTROL ASSEMBLY

CONNECTOR

MAGNETO

IGNITION G2

IGNITION

COIL T1

FUEL PUMP E2

(FUEL SHUTOFF - LPG)

FUEL SHUTOFF

SPARK PLUG E1

FIGURE 6-12. SPEC B RUN MODE

6-22

Page 44

WARNING

TABLE 6-10. BEGIN SPEC B CONTROL TROUBLESHOOTING – RUN MODE

Trouble Possible Cause Corrective Action Section/

Page

a. Defective battery condition meter. meter and ground. Use the following to b. Defective zener diode inside remote determine fault:

control. If reading equals battery voltage

minus 10 volts, battery condition meter is defective.

3b. If reading does not equal battery

voltage minus 10 volts, zener diode is defective.

4. Meters and switch function properly but 4. Replace remote Start/Stop switch (S2). run lamp does not illuminate. Lamp (internal to switch) is burned out.

assembly (A1). If voltage is present, check continuity

6. Too much DC load (over 2–amps) of remote control wiring. connected to the remote output. 6. Turn off the genset, disconnect the

remote control, and check for shorts or too many remote accessories.

6-23

Page 45

Begin Spec B Battery Charge Mode – 50 Hz Only

With the genset running, AC voltage is produced in the B1-B2 windings for the battery charge circuit in the 50 Hz models only. The 60 Hz Spec B models do not have battery charging.

• The AC output voltage from the B1-B2 winding is converted to DC voltage when it passes through the battery

charger assembly (VR2). The 12-volt DC output (ten-ampere maximum) is used to charge the battery and supply power to the control assembly (A1) and its outputs.

BATTERY CHARGER

ASSEMBLY VR2

B+

REMOTE CONTROL

STATOR

CONNECTORS

BATTERY BT1

FUSE F1

START/STOP SWITCH S1

BCEF

CONTROL

ASSEMBLY A1

FIGURE 6-13. SPEC B BATTERY CHARGE MODE – 50 Hz MODELS ONLY

P1 CONNECTOR

J1 CONNECTOR

ES2017-4s

6-24

Page 46

WARNING

TABLE 6-11. BEGIN SPEC B CONTROL TROUBLESHOOTING – BATTERY CHARGE MODE

Trouble Possible Cause Corrective Action Section/

Page

Low Battery 1. Weak or discharged battery due to: Voltage a. No battery charging. 1a. Spec B 60-Hz models require a battery

b. Low electrolyte level in battery. charger. These models do not have a c. Long periods of non-use. battery charge winding. d. Improperly wired battery. 1b. Replenish electrolyte and recharge e. Load connected to battery while battery.

genset is turned off. 1c. Connect a separate battery charger to

f. Too much DC load on genset bring battery up to full charge.

starting battery. 1d. Reconnect and check battery connec-

tion.

1e. Disconnect load and recharge

battery.

1f. Remove other DC loads from genset

starting battery.

2. 50 Hertz only: Genset 2a. Check all wiring connections between charging circuit not functioning due to: the generator B1-B2 windings and the a. Open wire connection in charging Battery B+ connection, including all

circuit (see Figure 6-13). connections to battery charger (VR2). b. Battery Charger (ZR2) defective. 2b. Refer to battery charger (VR2) test. 7-9 c. Generator B1-B2 defective. 2c. Refer to generator test section. 9-8

NOTE: The battery charging circuit is not available on the Spec B (or later) 60 Hz models. Spec B 50 Hz models have a maximum 10-amp, 12-VDC output designed to maintain and charge the genset starting battery.

6-25

Page 47

Begin Spec B Stop Mode

Momentarily pushing the Start/Stop switch (S1) to the Stop position begins the stop mode with the following results:

• Control assembly (A1) de-energizes the ignition enable circuit, grounding the magneto (G2) ignition circuit to

stop the engine.

• Control assembly (A1) also opens the circuit to the fuel pump (E2), the fuel shutoff solenoid (E3), and to the

remote control.

• Control assembly (A1) start disconnect senses a drop in voltage from the output voltage and activates the

remote stop latch to prevent restart during the stop mode.

CONTROL ASSEMBLY A1

P1 CONNECTOR

START/STOP SWITCH S1

BATTERY BT1

FUSE F1

FUEL PUMP E2

(FUEL SHUTOFF - LPG)

FUEL SHUTOFF E3

J1 CONNECTOR

MAGNETO

IGNITION G2

IGNITION

COIL T1

FIGURE 6-14. SPEC B STOP MODE

6-26

SPARK PLUG E1

Page 48

WARNING

TABLE 6-12. BEGIN SPEC B CONTROL TROUBLESHOOTING – STOP MODE

Trouble Possible Cause Corrective Action Section/

Page

b. Remote Start/Stop switch faulty.

6-27

Page 49

GENERATOR TROUBLESHOOTING

and 6-2 on pages 6-2 and 6-3 show the location

of the generator components. Refer to the wiring Use the following troubleshooting guide to help locate problems related to the generator. Figures 6-1

WARNING

Many troubleshooting procedures present hazards that can result in severe personal inju-

diagrams in Section

for wiring connections.

12. Wiring Schematic/Diagram

ry or death. Only qualified service personnel with knowledge of fuels, electricity, and machinery hazards should perform service procedures. Review safety precautions on page iii.

TABLE 6-13. GENERATOR TROUBLESHOOTING

Trouble Possible Cause Corrective Action Section/

Page

No AC Output 1. Open circuit breaker. 1. Locate cause of overload and correct Voltage as required. Reset breaker.

Note: This 2. Open circuit between voltage 2. Check for good wiring connections condition may regulator and brush block. betwen regulator and brush block. cause the genset 3. Open circuit between stator connec- 3. Check for good wiring connections to stop when tions Q1 or Q2 and voltage regulator. between regulator and stator. start switch S1 (This condition will give approx. is released. 30 VAC output voltage in start mode.)

4. Open circuit between battery Pos. (+) 4. Check for continuity between control and voltage regulator pin 7 for connector P1-5 and regulator connector field flash. P4-7 (Spec A) or J1-9 to P4-7 (Spec B)

If connections are good and 12 VDC is not present at voltage regulator pin 7 during start, control assembly A1 is defective.

5. Brushes not making good contact 5. Check brushes for wear and for contact. 9-12 with slip rings.

6. Slip ring surface is rough or pitted. 6. Check slip rings.

7. Defective generator, control assembly 7. Perform field voltage test. 9-8 A1, or voltage regulator VR1.

AC Output 1. Engine governor out of adjustment. 1. Refer to governor adjustments in 8-9 Voltage Too Section 8. Low

2. Brushes worn or not making good 2. Check length of brushes and replace 9-12 contact with slip rings. if worn excessively. Check slip rings.

3. Poor wiring connections to 3. Check for good wiring connections voltage regulator. between the voltage regulator and the

brush block and between stator connections Q1and Q2. Correct if required.

4. If generator frequency is within 4. Replace electronic voltage regulator. specified limits but voltage is incorrect, voltage regulator is defective.

6-28

Page 50

Spec A Generator AC Output Mode

When the engine starts and begins to come up to speed, AC voltage is produced in the battery charge winding B1-B2, the quadrature winding Q1-Q2 and in the AC windings T1-T2. These outputs perform the following functions:

• The battery charge winding B1-B2 is used to power the control assembly (A1), fuel pump (E2), the remote con-

trol, and to prevent discharge of the genset starting battery during genset operation. This output is not sufficient to charge a low or dead battery. The control assembly A1 monitors this voltage as part of the start disconnect function.

• The quadrature winding Q1-Q2 output voltage is fed to the voltage regulator VR1 where it is rectified into DC

voltage and fed back to the rotor through the brushes to cause further voltage buildup. Voltage buildup is controlled by the voltage regulator that senses the AC output voltage. The regulator continually measures the output voltage and compares it to an internal reference voltage. When the output voltage exceeds the reference, the regulator causes the current in the rotor to decrease until the proper voltage is obtained.

• The AC windings T1-T2 provide the 120 VAC output voltage through the circuit breaker CB1.

BATTERY BT1

BRIDGE

RECTIFIER CR1

J1 CONNECTOR

STATOR

CONNECTORS

BATTERY CHARGE

RESISTOR R1

CONTROL

ASSEMBLY A1

P1 CONNECTOR

P4 CONNECTOR

FUSE F1

START/STOP

SWITCH S1

VOLTAGE

REGULATOR VR1

J4 CONNECTOR

BRUSH

BLOCK

CIRCUIT BREAKER CB1

L2 (NEUT)

L1 (LOAD)

FIGURE 6-15. SPEC A GENERATOR OUTPUT MODE

6-29

GND

120 VAC

Page 51

Spec B Generator AC Output Mode

When the engine starts and begins to come up to speed, AC voltage is produced in the battery charge winding B1-B2 (50 Hz only), the quadrature winding Q1-Q2 and in the AC windings T1-T2 (T3-T4 50 HZ). These outputs perform as follows:

• The battery charge winding B1-B2 is provided on the 50 Hz models only to power battery charger (VR2).

• The quadrature winding Q1-Q2 output voltage is fed to the voltage regulator VR1 where it is rectified into DC

• The AC windings T1-T2 provide the output AC voltage (60 Hz models) or T1-T2, T3-T4 (50 Hz models) through

the circuit breaker CB1.

START/STOP

SWITCH S1

BATTERY

BT1

ASSEMBLY A1

ES2017-6s

CONTROL

P1 CONNECTOR

STATOR

CONNECTORS

BRUSH BLOCK

J1 CONNECTOR

P4 CONNECTOR

J4 CONNECTOR

CIRCUIT BREAKER CB1

FUSE

VOLTAGE

REGULATOR VR1

L2 (NEUT)

GND

L1 (LOAD)

120 VAC

FIGURE 6-16. SPEC B GENERATOR OUTPUT MODE (60 HERTZ MODEL SHOWN)

6-30

Page 52

WARNING

Many troubleshooting procedures present hazards which can result in severe personal injury or death. Only qualified service personnel with knowledge of fuels, electricity, and machinery hazards should perform service procedures. Review safety precautions on page iii.

TABLE 6-14. GENERATOR TROUBLESHOOTING

Trouble Possible Cause Corrective Action Section/

Page

AC Output 1. Engine governor out of adjustment. 1. Refer to Voltage Too High 2. If generator frequency is within 2. Refer to Table 8-1 for voltage/frequency

specified limits but voltage is incorrect, specs. Replace electronic voltage electronic voltage regulator is defective. regulator.

Noisy 1. Loose brush holder. 1. Tighten brush holder. Generator 2. Worn rotor bearing. 2. Replace rotor bearing. 9-13

3. Rotor and stator rubbing together 3a. Check for varnish lumps between due to: rotor and stator, remove as required. a. Varnish lumps. 3b. Follow specified assembly procedures 9-7 b. Rotor misaligned with crankshaft. to correct rotor to crankshaft

alignment.

Generator 1. Generator overloaded due to 1. Replace circuit breaker. Do not Overheats defective circuit breaker. exceed specified load when

operating genset.

Governor Adjustments

8-9

2. Airflow restricted due to dirt or 2. Clear away all dirt or debris as required. debris covering vent openings in stator housing.

3. Stator windings covered with oil 3. Clean stator windings. or dirt.

4. Defective rotor or stator windings. 4. Test each component for open, 9-8

grounded, or shorted windings and replace if defective.

5. Loose or missing service access cover 5. Check for proper fit of service access or improper seal around the endbell cover and check seal around endbell. assembly.

6. Improper installation due to: a. Insufficient air inlet size. 6a. Make sure air inlet is not blocked and b. Air inlet location allowing that it is properly sized (refer to

recirculation. Installation Manual).

6b. Make sure that air outlet is not blocked

and check for recirculation of outlet air.

6-31

Page 53

ENGINE PRIMARY SYSTEMS

TROUBLESHOOTING

Use the following troubleshooting guide to locate problems with the engine primary systems. Many of

Poor engine performance is often caused by a dirty carburetor. Make certain that the carburetor is clean before troubleshooting for performance problems.

the primary systems can be serviced without removing the genset from the vehicle.

WARNING

TABLE 6-15. TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Trouble Possible Cause Corrective Action Section/

Page

Engine Runs 1. Dirty air or fuel filter. 1. Check and replace if necessary. Rough:

2. Contaminated fuel. 2. Drain fuel tank, clean the fuel system and refill with fresh fuel.

3. Lean fuel mixture due to:

a. Incorrectly adjusted 3a. Adjust carburetor main 8-14

Fuel mixture screws. and idle adjustment screws. b. Dirt in carburetor. 3b. Disassemble carburetor and clean 8-15 c. Vacuum leak. all internal passages. Replace filter.

3c. Locate and correct leak.

d. Gasket failure. 3d. Replace gasket.

4. Faulty ignition due to: a. Worn or fouled spark plug. 4a. Replace spark plug. b. Poor magneto or coil connections. 4b. Check magneto and coil connections. c. Faulty ignition components. 4c. Perform Ignition Spark Check. 8-6 d. Faulty plug wire. 4d. Check spark plug wire and boot. e. Incorrect ignition timing. 4e. Rotor or fan hub improperly installed.

Engine 1. Lean fuel mixture due to: 1a. Adjust carburetor main and idle 8-14 Backfires a. Incorrectly adjusted fuel mixture screws. Through adjustment screws. 1b. Disassemble carburetor and clean 8-15 Carburetor b. Dirt in carburetor. all internal passages.

c. Vacuum leak. 1c. Locate and correct leak.

2. Mechanical engine defect 2. Perform Leak Down Test. 10-1 (intake valve defect).

3. Faulty ignition due to: 3. Reset spark plug gap. incorrect spark plug gap.

6-32

Page 54

WARNING

TABLE 6-16. TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Trouble Possible Cause Corrective Action Section/

Page

Engine 1. Rich fuel mixture due to: 1a. Adjust carburetor main and idle 8-14 Backfires a. Incorrectly adjusted fuel mixture screws. Through adjustment screws. 1b. Check choke assembly. 8-17 Muffler When b. Choke sticking or out of adjustment. Running c. Restricted air filter (LPG models). 1c. Replace air filter. 8-11

2. Mechanical engine defect 2. Perform Leak Down Test. 10-1 (exhaust valve defect).

3. Faulty ignition due to: 3. Reset spark plug gap. Incorrect spark plug gap.

Engine Lacks 1. Dirty air filter. 1. Replace air filter. 8-11 Power

2. Restricted fuel flow due to: a. Plugged fuel filter or 2a. Replace fuel filter. 8-19 b. Faulty fuel pump 2b. Test fuel pump and replace if faulty. 8-19 c. LPG - regulator or fuel solenoid 2c. Refer to LPG Fuel System, section 8.

dirty or defective.

3. Exhaust system blocked or restricted. 3. Locate and remove blockage, clean

spark arrester screen.

4.Carburetor air preheater set incorrectly. 4. Check automatic preheater setting. 8-11

5. No load speed set too low. 5 . Adjust governor setting. 8-9

6. Incorrect fuel mixture due to: a. Incorrectly adjusted fuel 6a. Adjust carburetor main and idle 8-14

mixture screws. adjustment screws.

b. Dirt or varnish in carburetor. 6b. Disassemble carburetor and clean 8-15

all internal passages.

7. Incorrect valve lifter clearance or 7. Adjust valve clearance, if problem 10-7 defective valve. continues inspect valves.

8. Excessive engine wear. 8. Perform Leak Down Test. 10-1

6-33

Page 55

WARNING

TABLE 6-17. TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Trouble Possible Cause Corrective Action Section/

Page

Engine 1. Restricted airflow due to dirt, debris 1. Clear air inlet and outlet areas. Do not Overheats or insulation blocking air inlet or outlet. store anything in compartment area.

2. Dirt or oil on engine cooling fins. 2. Clean all dirt and oil from engine cooling fins.

3. mCooling fan plugged or broken. 3. Inspect cooling fan, clean or replace as needed,

4. Lean fuel mixture due to:

a. Incorrectly adjusted fuel 4a. Adjust carburetor main and idle 8-14

mixture screws. adjustment screws.

b. Dirt or varnish in carburetor. 4b. Disassemble carburetor and clean 8-15

all internal passages.

5. Loose or missing service access cover 5. Check for proper fit of service access

or improper seal around the endbell cover and check seal around endbell. assembly.

6. Improper installation due to:

a. Insufficient air inlet size. 6a. Make sure air inlet is not blocked and b. Air inlet location allowing that it is properly sized (refer to

recirculation. Installation Manual).

6b. Make sure that air outlet is not blocked

and check for recirculation of outlet air.

Black Exhaust 1. Rich fuel mixture due to: 1a. Replace air filter. 8-11 Smoke a. Dirty air filter. 1b. Clean choke and choke linkage.

b. Choke sticking. 1c. Adjust carburetor idle and main 8-14

c. Incorrectly adjusted fuel mixture adjustment screws.

screws. 1d. Disassemble carburetor and clean all 8-15

d. Dirt or varnish in carburetor. internal passages.

White or Blue 1. Oil level too high. 1. Lower oil level. Exhaust Smoke 2. Contaminated fuel. 2. Drain and refill fuel tank.

3. Excessive engine wear. 3. Perform Leak Down Test. 10-1

6-34

Page 56

WARNING

TABLE 6-18. TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Trouble Possible Cause Corrective Action Section/

Page

Engine Hunts 1. Fuel supply problem caused by: 1a. Check fuel pump and replace 8-19 or Surges a. Faulty fuel pump. if defective.

b. Contaminated fuel supply. 1b. Drain and refill fuel supply. c. Vapor locking. 1c. Let genset cool down. Check for

blockage air inlet or outlet or improper

fuel system installation. d. Plugged fuel filter. 1d. Replace fuel filter. 8-19 e. Carburetor passages plugged. 1e. Clean passages or replace pilot jet. 8-15

2. Incorrect fuel mixture due to: 2a. Adjust carburetor main and 8-13 a. Incorrectly adjusted idle adjustment screws.

fuel mixture screws. 2b. Disassemble carburetor and 8-14

b. Dirt or varnish in carburetor. clean all internal passages.

3. Governor problem due to: 3a. Check linkage alignment.Make sure 8-9 a. Sticking or binding governor linkage. it does not touch other parts. Clean b. Incorrect governor adjustment. and lubricate linkage. c. Faulty governor spring. 3b. Adjust speed and sensitivity settings. 8-9 d. Governor mechanism worn 3c. Replace governor spring.

excessively. 3d. See

Block Assembly

Governor

in Section

10. Engine

10-8

High Oil 1. Oil viscosity too light or oil is diluted. 1. Drain oil and refill with correct Consumption viscosity oil. (Note: New 2. Crankcase breather valve is 2. Clean crankcase breather 8-8 engines can dirty, faulty or improperly installed. and replace if defective. have high oil consump- 3. Oil leaks. 3. Locate source of leak and tion during repair as required. break-in)

4. Excessive engine wear. 4. See Section

5. Light loading. 5. Do not run genset at no-load for long

periods of time.

6. Intake valve seal worn or defective. 6. Replace intake valve seal. 10-7

10. Engine Block Assembly

6-35

Page 57

WARNING

TABLE 6-19. TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Trouble Possible Cause Corrective Action Section/

Page

Engine Shuts 1. Low oil level. 1. Add oil as required. Down and Will Not Restart 2. Low oil level switch is defective 2. Check low oil level switch.

(Spec A-F, if applicable).

(Also see 3. Worn spark plug. 3. Clean or replace spark plug. Control Trouble- 4. Faulty fuel system - flooded. 4. Refer to shooting table 6-4) 5. Choke not opening. 5. Check choke operation. 8-17

6. Faulty ignition system. 6. Check for spark. 8-6

Engine Runs 1. Fouled spark plug. 1. Clean or replace spark plug. On After 2. Engine carbon build-up. 2. Remove carbon from engine. Shutdown

Gasoline Fuel System.

8-11

6-36

Page 58

7. Control

INTRODUCTION

This section covers control operation, component locations, basic troubleshooting and test procedures. The control consists of the circuitry used for starting, monitoring fault conditions, instrumentation, battery charging, and stopping.

CONTROL DESCRIPTION

The control circuitry consists of the following components. See Figure 7-1.

• Panel mounted Start/Stop Switch (S1)

• Start Solenoid (K1)

• Control Fuse (F1)

• Circuit Breaker (CB1)

• Control Assembly (A1)

• Optional Remote Start/Stop Control (A2, A3)

• Battery Charge Resistor (R1)

• Rectifier Bridge (CR1)

• Battery Charger Assembly (VR2)

• Transformer (T1)

Start/Stop Switch (S1)

The Start/Stop switch (S1) is a single-pole doublethrow (SPDT) rocker type switch used for starting or stopping the genset. Holding the switch in the Start position will initiate engine cranking. Pushing the switch to the Stop position will initiate the stop function. The switch will automatically return to the center (Run) position when released.

BATTERY CHARGE

RESISTOR R1

M1899-3s

BRIDGE RECTIFIER CR1

START RELAY K1

CONTROL PANEL

CONTROL

ASSEMBLY A1

FIGURE 7-1. SPEC A CONTROL COMPONENT LOCATIONS

7-1

Page 59

Start Solenoid (K1)

The start solenoid (K1) is used for closing and opening the circuit between the battery and the starter motor. The start solenoid has heavy duty contacts that handle the high current draw of the starter during cranking.

Control Fuse (F1)

A 5-amp fuse provides protection for the control wiring and remote wiring from a short circuit. The control fuse is mounted on the front of the control panel.

Circuit Breaker (CB1)

The standard 30-amp circuit breaker protects the generator AC windings from a short circuit or overload. The circuit breaker is located on the control

panel. If an overload occurs, the breaker can be reset after all loads are removed from the genset.

Control Assembly (A1)

The control assembly consists of a printed circuit board with components and relays that are potted (encapsulated in a nonconductive material) to protect them from moisture. The control assembly is mounted near the air inlet for cooling. See Figure 7-1 on Page 7-1 and Figure 7-2.

The control provides the following functions:

• Starter Solenoid Output

• Fuel Pump Output

• AVR Field Flash Output

• Remote Running Output

• Ignition Enable

M1899-3s

CONTROL

ASSEMBLY A1

START RELAY K1

BATTERY CHARGER

ASSEMBLY (VR2)

50 HERTZ ONLY

CONTROL PANEL

FIGURE 7-2. BEGIN SPEC B CONTROL COMPONENT LOCATIONS

7-2

Page 60

Optional Remote Control (A2, A3)

CONTROL OPERATION

The remote control is an optional accessory that allows the genset to be started, monitored, and stopped from a remote location. The deluxe control (A3) includes a running time meter and a battery condition meter. Remote control panels are mounted inside the vehicle.

Rectifier Bridge (CR1) – Spec A Only

The rectifier bridge consists of four diodes connected in a bridge circuit to form a full-wave voltage rectifier. The bridge circuit rectifies the AC voltage from the generator battery winding (B1-B2) to supply DC voltage for battery charging.

Battery Charge Resistor (R1) – Spec A Only

The battery charge resistor limits the battery charge rate to a maximum of one ampere.

Battery Charger Assembly (VR2) – Begin Spec B 50 Hz Only

The battery charger assembly rectifies the AC voltage from the generator battery winding (B1-B2) to supply DC voltage for battery charging.

Transformer (T1) – Begin Spec B 50 Hz Only

The transformer provides isolation required for some 50 Hz reconnection applications. (See Figure 6-2 on Page 6-3 for transformer location.)

The schematic diagrams in Section

Schematic/Diagram

circuit description. Always refer to the specific wiring diagram that corresponds to the model and spec number of the genset when troubleshooting.

can be used to help follow the

12. Wiring

Start Mode

Holding the Start/Stop switch (S1) in the Start position activates the control assembly (A1) by closing the start signal input circuit. While the Start/Stop switch is held, the control assembly supplies the following outputs and results:

• Energizes the start solenoid (K1) causing the start solenoid contacts to close energizing the starter. The starter begins to crank the engine to initiate starting.

• Energizes the fuel pump (E2), the fuel pump begins pumping fuel to the carburetor for engine operation.

Begin Spec B models: the fuel shutoff solenoid E3 is energized allowing fuel to pass through the carburetor.

LPG models: the fuel shutoff solenoid (E2) and priming solenoid (K3) are energized to allow fuel flow to the carburetor.

• Flashes the generator field winding to ensure that there is adequate magnetism to induce generator voltage buildup.

• Enable the ignition circuit, this opens a ground path through the control assembly to the magneto assembly (G2) so output from the magneto will energize the ignition coil (T1). The ignition coil energizes the spark plug (E1) for ignition.

7-3

Page 61

Run Mode

When the engine starts, release the Start/Stop switch and it will return to the center Run position. The following control assembly functions occur:

• Voltage from the battery is replaced by output voltage from the generator (when the engine comes up to speed) so the control remains energized on Spec A and begin Spec B 50 Hz only.

• Start solenoid (K1) is de-energized, opening the circuit to the starter motor (M1) to stop cranking. (The start disconnect is activated at approximately 2500 rpm.)

• Fuel Pump (E2) remains energized during the run condition. Fuel shutoff solenoid (E3) remains energized on begin Spec B models.

• LPG model: Priming solenoid (K2) is de-energized.

• Field flash is no longer required and is turned off.

• Ignition Enable remains on. Output from the magneto assembly (G2) energizes the ignition coil (T1) to provide spark.

• Remote run output energizes the running time meter and the battery condition meter in the optional deluxe remote control (A2).

A low oil level will cause the low oil level switch (S2) to close. This closes a ground path to the magneto assembly (G2) eliminating ignition spark and preventing the engine from operating. If the oil level goes below the low oil level during operation, the genset will shut down.

Charging Circuit

A 12-volt DC output (one-ampere maximum on Spec A or ten-ampere maximum Spec B 50 Hz) from the generator is used to prevent discharge of the genset starting battery during genset operation. Spec B 60-Hz models do not have a battery charge winding.

Stopping

Pressing the Start/Stop switch (S1) to the Stop position de-energizes the ignition enable circuit and grounds the magneto assembly (G2) output. This causes the engine to stop running. The Stop position also activates the remote stop latch feature preventing restart. At the same time the fuel pump is de-energized.

LPG models: the fuel shutoff solenoid (E2) is de-energized stopping fuel flow to the carburetor.

7-4

Page 62

CONTROL COMPONENT TESTS

The following control component checks can be made to verify if components are defective. Disconnect the starting battery cables, negative (–) cable first, before performing these tests.

WARNING

shock can cause severe personal injury or death. Disconnect both genset starting battery cables before performing maintenance. Remove the negative (–) battery cable first and connect it last to reduce the risk of arcing.

Accidental starting or electrical

Start/Stop Switch (S1)

Disconnect the P1 (or J1 for Spec B) connector from control assembly (A1). See Figure 7-3. Continuity should be measured between pin 1 and pin 3 (pin 13 and pin 7 for Spec B) when the switch is held in the Start position. Continuity should be measured between pin 2 and pin 3 (pin 1 and pin 7 for Spec B) when the switch is held in the Stop position. An open circuit should be measured between pins 1, 2, and 3 (13, 7 and 1 Spec B) when the switch is in the center Run position.

If the switch tests good also check the control connector P1 to J1 connections to make sure they are making a good connection.

If an abnormal reading is obtained, check the continuity between the connector pins and the switch. (Use an ohmmeter with pointed test leads to pierce the insulation at the back of the switch on Spec A models).

START/STOP SWITCH S1

SPEC A

P1 CONNECTOR

M1899-4s

BEGIN SPEC B

J1 CONNECTOR

M1899-4s

FIGURE 7-3. START/STOP SWITCH

7-5

Page 63

Start Solenoid (K1)

A check can be made by measuring the resistance of the coil terminals I and S (Figure 7-4). With the harness leads removed, the coil should read between 3 and 5 ohms. If an abnormal reading is measured, replace the Start Solenoid.

If the coil checks good and a problem with the solenoid is still suspected, remove the leads from the side terminal posts. An open circuit should be measured between the side terminal posts with the coil de-energized. With 12 VDC applied across the coil (I and S terminals) the solenoid should be energized and continuity should be measured between the side posts.

Control Assembly (A1)

WARNING

Electrical shock can cause severe personal injury or death. Do not touch the voltmeter or any wiring when the genset is operating. Attach and remove meter leads only when the genset is stopped.

Tables 7-1 and 7-2 on Page 7-7 list the control outputs at the P1/J1 connector plug for each control mode. Measure control output voltages between the connector pin listed and ground. Refer to the correct chart for Spec A and for Spec B models.

Battery B+ voltage must be present at the Control Assembly J1-10/P1-10 at all times. If battery voltage is present at the J1-10/P1-10 connector and the control outputs are not present, check the J1/P1 connector and the Start/Stop switch (S1). If the connector and switch check good, replace the Control Assembly with a new Control Assembly and recheck genset operation.

The Control Assembly consists of a printed circuit board with components and relays that are potted (encapsulated in a nonconductive material) to protect them from moisture. It is difficult to isolate individual components on the control assembly for testing. Use Section

6. Troubleshooting

to identify possible problems in the control circuit. If a problem with the Control Assembly is suspected, use the control circuit board tester if available, or check the control outputs with a voltmeter. Figure 7-5 on Page 7-7 shows the Control Assembly and the P1/J1 connectors. Voltages can be checked using a voltmeter with long test prods.

TERMINAL

POSTS

START RELAY K1

FIGURE 7-4. SOLENOID CHECK

7-6

Page 64

TABLE 7-1. SPEC A CONTROL OUTPUTS

CONTROL OUTPUT CONTROL MODE (CONNECTOR PIN) CRANK RUN STOP

STARTER SOLENOID ≥9 VDC 0 VDC 0 VDC (J18/P18) FUEL PUMP ≥9 VDC ≥9 VDC 0 VDC (J112/P112) AVR FIELD FLASH (J15/P15) REMOTE RUN 0 VDC ≥9 VDC 0 VDC (J25, J26)

≥9 VDC 0 VDC 0 VDC

CONTROL

ASSEMBLY A1 -

SPEC A

P1 CONNECTOR

J1 CONNECTOR

TABLE 7-2. BEGIN SPEC B CONTROL OUTPUTS

CONTROL OUTPUT CONTROL MODE (CONNECTOR PIN) CRANK RUN STOP

STARTER SOLENOID ≥9 VDC 0 VDC 0 VDC (J16/P16) FUEL PUMP ≥9 VDC ≥9 VDC 0 VDC (J12/P12) FUEL SHUTOFF SOL. ≥9 VDC ≥9 VDC 0 VDC (J13/P13) AVR FIELD FLASH ≥9 VDC 0 VDC 0 VDC (J19/P19) REMOTE RUN 0 VDC ≥9 VDC 0 VDC (J25, J26)

CONTROL

ASSEMBLY A1 -

BEGIN SPEC B

J1 CONNECTOR

P1 CONNECTOR

FIGURE 7-5. CONTROL ASSEMBLY (A1) CHECK

7-7

Page 65

Resistor (R1) – Spec A Only

The battery charge resistor can be checked with an ohmmeter. Disconnect the leads from the resistor and measure the resistance between terminals on one end to the resistor and the terminals on the other end. The resistor should measure between 4 and 6 ohms. If an abnormal reading is measured, replace the resistor.

Diode Bridge (CR1)

The diode bridge consists of four diodes connected in a bridge circuit (Figure 7-6). The diode bridge can be checked with a diode checker. Remove all of the leads from the diode bridge and check each diode individually. Continuity should be indicated in the forward bias direction and an open circuit should be indicated in the reverse bias direction (refer to your meter instruction manual). If any of the diodes check bad, replace the diode bridge.

BRIDGE RECTIFIER SCHEMATIC

ES2015s

7-8

SPEC A BRIDGE RECTIFIER CR1

FIGURE 7-6. DIODE BRIDGE CR1 CHECK

Page 66

Battery Charger Assembly (VR2) – Begin Spec B, 50 Hz Only

The battery charger is located on the left side of the genset housing. The battery charger can be checked with a voltmeter. A voltage measurement between the B+ terminal and ground (Figure 7-7), with the genset off should read the starting battery voltage (approximately 12 VDC). With the genset running a reading between the B+ terminal and ground should be slightly more than the first reading (12.5 to 14 VDC).

If the same or less voltage is measured, connect the voltmeter between the two AC terminals to measure the input voltage from the B1-B2 battery charge winding. During set operation voltage from the B1-B2 battery charge winding should be approximately 17 to 19 VAC. If this reading is obtained and charger output voltage does increase when the genset is started, replace the battery charger. If low or no voltage is measured between the AC terminals, check the wiring harness connections and refer to the generator test section.

GROUND

CONNECTION

B+

FIGURE 7-7. BATTERY CHARGER ASSEMBLY

(VR2)

7-9

Page 67

Transformer (T1) – Begin Spec B, 50 Hz Only

The transformer (see /Figure 7-8) is located on the backside of the genset (see Figure 6-2 on Page 6-3). The transformer can be checked with an ohmmeter. Isolate the transformer leads from the circuit and measure the resistance between H1 - H2 primary winding. The primary should measure 440 to 540 ohms. Measure the resistance between X1 - X2 secondary winding. The secondary should measure 225 to 275 ohms. If an abnormal reading is measured, replace the transformer.

TRANSFORMER T1

TRANSFORMER T1 SCHEMATIC

FIGURE 7-8. TRANSFORMER (T1)

7-10

Page 68

8. Primary Engine Systems

INTRODUCTION

This section describes the engine primary systems service procedures. Many of the primary systems can be serviced without removing the genset from the vehicle. Poor engine performance is often caused by a dirty carburetor. Make certain that the carburetor is clean before troubleshooting for performance problems.

Primary engine systems include:

• Cooling system

• Exhaust system

• Ignition system

• Crankcase ventilation system

• Governor

• Fuel system

• Electric starter

COOLING SYSTEM

The genset requires a constant airflow to cool the engine and generator during operation. A centrifugal fan on the generator end of the genset provides the required airflow. The fan draws cooling air through the air inlet, into the generator and forces it across the engine cooling fins. The air is discharged through the air outlet. See Figure 8-1.

Inspection

Inspect the air inlet and outlet passages. Remove the access panel and inspect the engine and control area. If the engine is clean and the air inlet area is clean, disassembly for engine cleaning will not be necessary. If debris is visible, proceed to the

sembly

section following.

Disas-

Disassembly

Remove the genset as described in

Guidelines

1. Follow the genset disassembly procedures in

2. Inspect and clean the fan hub assembly using

3. Remove the top and bottom air guide housings

4. Use a brush or low pressure compressed air to

on Page 5-2.

Section bly removal.

a brush or low pressure compressed air. If the cooling fins are damaged, replace the fan hub assembly as described in Section

tor

(cowling) to access the engine cooling fins for cleaning.

remove any dirt or debris that may be lodged on the engine cooling fins.

9. Generator

through the scroll assem-

Set Removal

9. Genera-

WARNING

Cooling air can contain poisonous exhaust gases that can result in severe personal injury or death. Never use discharged cooling air to heat the vehicle interior.

The air inlet is sized to allow the required flow rate of cooling air. The air inlet opening and the air discharge opening must be kept free of any obstructions to avoid restricting airflow. Dirt, dust, or other debris that clog the air openings should be removed during periodic maintenance. Dirt might also become lodged between the cooling fins on the engine block and cylinder head. If this happens, heat transfer is greatly reduced and overheating can occur. The cooling system consists of the genset housing and base assembly enclosure, insulation duct, scroll assembly, fan hub assembly, and air duct. The following section covers service procedures for the cooling system .

8-1

AIR

INLET

AIR

M1900-3s

FIGURE 8-1. COOLING AIRFLOW (SPEC B

SHOWN)

OUTLET

Page 69

Assembly

Assemble cooling system in reverse order of disassembly. Follow the generator assembly instructions (Section sembly.

9. Generator

) for installing the fan hub as-

The muffler is a spark arrester type muffler that is US Forest Service Approved and meets code requirements. Failure to provide and maintain a spark arrester muffler can be in violation of the law. Contact an Onan distributor for approved replacement exhaust parts.

CAUTION

Overheating can result in engine damage. To avoid overheating, never operate the genset with any of the cooling system components removed.

EXHAUST SYSTEM

The condition of the exhaust system is extremely critical on RV gensets because of the possibility of exhaust gases entering the vehicle. The exhaust system must not have any leaks and it must be well supported. The tailpipe must extend 1 inch (25.4 mm) beyond the the perimeter of the vehicle and it must not terminate so exhaust can enter the vehicle.

WARNING

monoxide, an odorless and colorless gas that can cause severe personal injury or death. Make certain that the exhaust components are in good condition and that there are no leaks.

The exhaust system consists of the muffler, the exhaust pipe, and the clamps and hangers needed for installation of the exhaust pipe. On Begin Spec B, the muffler has a flexible inlet pipe. On Spec A, the muffler has a flexible outlet pipe. Figure 8-2 on Page 8-3 shows a typical exhaust system for a compartment mount genset. The following section covers the service procedures for the exhaust system.

The exhaust system must be serviced immediately if inspection reveals leaking joints or connections, loose fasteners, or broken or damaged components.

Exhaust gasses contain carbon

WARNING

Inhaling exhaust gases can cause severe personal injury or death. Modifying the exhaust system may let poisonous exhaust gases enter the vehicle. Use only Onan replacement parts to service the exhaust system. Unauthorized modifications will void the Onan warranty. Liability for injury or damages due to unauthorized modifications becomes the responsibility of the person making the modification.

Muffler Disassembly

1. Allow the exhaust system to cool down before servicing.

2. Loosen the exhaust pipe clamp securing the exhaust pipe to the genset.

3. Remove exhaust pipe hanger(s) and lower exhaust pipe.

4. Remove the genset from the vehicle and remove the outer housing. See

Guideslines

on Page 5-2.

Spec A:

5. Remove the bolts securing the muffler flange to the engine and the muffler outlet pipe to the base.

6. Remove the hardware securing the muffler bracket to the engine bracket. Remove the muffler and the exhaust gasket.

Begin Spec B:

Set Removal

Always replace worn components with new original equipment replacement parts. Do not attempt to repair a broken exhaust pipe or manifold by welding and do not replace worn out components with parts that do not meet factory specifications.

5. Remove the bolts securing the flexible exhaust manifold to the muffler.

6. Remove the screws securing the muffler to the base. Remove the muffler and the exhaust gasket.

8-2

Page 70

SPEC A MODELS

EXS1170-5s

SHORT RADIUS

ELBOW

SUPPORT

UBOLT CLAMP

HANGER BRACKET

(IF REQUIRED DUE TO

LENGTH OF TAILPIPE)

SUPPORT

TAILPIPE

BEGIN SPEC B MODELS

TAILPIPE

EXS1170-7s

FIGURE 8-2. COMPARTMENT MOUNT EXHAUST SYSTEM

Muffler Assembly

Obtain the required replacement parts including a new exhaust gasket. Install the muffler in reverse order of removal.

1. Install a new exhaust gasket. Secure the

SUPPORT

mounting hardware to the specified torque.

WARNING

Exhaust gas can cause severe personal injury or death. To prevent exhaust leaks, always install a new exhaust gasket, and replace corroded or worn clamps, straps, and hardware before leaks occur.

8-3

Page 71

2. Install the genset housing and reinstall the genset.

3. If replacing the original exhaust tailpipe, refer to the Tailpipe Recommendations section.

4. Attach the exhaust pipe to the exhaust outlet using a U-bolt type automotive muffler clamp marked 1-3/8 inch I.D. (Spec A) or 1-1/4 inch I.D. (Begin Spec B).

5. Attach an automotive type tailpipe hanger every 2 to 3 feet (0.6 to 0.9 meters). In addition, the exhaust system must be supported at or near the perimeter of the vehicle to prevent the tailpipe from being damaged and being pushed up under the vehicle skirt.

CAUTION

Excessive vibration transfer and exhaust pipe damage can be caused by angular mounting. Tailpipe hanger clamps must be mounted directly above the component being supported and not at an angle.

6. Run the genset for five minutes and check the entire exhaust system (visually and audibly) for leaks or excessive noise. Correct any problems immediately.

Tailpipe Recommendations

Tailpipes must meet several design specifications to provide safe genset operation. If replacing the tailpipe, make certain the replacement part is the same size and configuration as the original part. Refer to the following guidelines for selecting and locating the tailpipe.

WARNING

sult in severe personal injury or death. Exhaust gases can enter the vehicle interior if the tailpipe is damaged, missing, or improperly installed. Follow the recommended exhaust system replacement procedures.

Inhalation of exhaust gases can re-

WARNING

Hot exhaust components present the risk of fire that can result in severe personal injury, death or equipment damage. Follow the recommended clearances between the exhaust system and any combustible materials.

The exhaust system must be placed no closer than 3 inches (76 mm) from combustible material (wood, felt, cotton, organic fibers, etc.), or be so located, insulated or shielded that it does not raise the temperature of any combustible material more than 117° F (65° C) above the ambient air inlet temperature.

The exhaust system must extend a minimum 1 inch (25 mm) beyond the perimeter of the vehicle. Do not terminate the exhaust tailpipe under the vehicle. Be aware that any vent, window, storage compartment or opening that can be opened and that is not permanently sealed from the vehicle living space can be an avenue for carbon monoxide.

The tailpipe must not terminate so that any vent, window, or opening into the living area is within a six inch (152.4 mm) radius of the tail pipe as shown in Figure 8-3 on Page 8-5.

WARNING

Exhaust gas presents the hazard of severe personal injury or death. Do not terminate an exhaust pipe under the vehicle. The tailpipe must not terminate so that any vent, window, or opening into the living area is within a six inch (152.4 mm) radius of the tail pipe as shown in Figure 8-3 on Page 8-5. Keep all openings closed when the genset is running.

To reduce the chance of damaging the tailpipe and emitting exhaust gases under the vehicle, make certain that no part of the exhaust system intrudes into the departure angle or approach angle of the vehicle, unless it is protected by a skid bar or other protection device. The shaded areas in Figure 8-3 illustrate typical mounting locations.

Spec A:

or stainless steel tubing for tailpipe.

Begin Spec B:

18-gauge aluminized steel or stainless steel tubing for tailpipe.

Do not use flexible tailpipe since it might break due to road shock and vibration.

Use 1-1/2 inch O.D., 18-gauge aluminized

Use 1-1/4 inch O.D. (1-1/8 inch I.D.)

WARNING

Exhaust gas presents the hazard of severe personal injury or death. Do not mount any portion of the exhaust system into the approach or departure angle unless it is adequately protected. Use only Onan-specified exhaust equipment with the genset. Use a sufficient number of hangers to prevent dislocation of the system.

8-4

Page 72

Do not terminate the exhaust tailpipe under the fuel tank fill spout to prevent spilled fuel from being ignited by a hot tailpipe.

SEALED WINDOW

TAILPIPE

(RV REAR VIEW)

CAUTION

Excessive exhaust back pressure

can cause engine damage. If tailpipe deflector is used, make sure it is large enough to prevent back pressure.

SKID BARS

DEPARTURE

ANGLE

GROUND

SHADED ZONE IS AREA

OF RECOMMENDED

TAILPIPE INSTALLATION

6 IN.

(152.4 mm)

NO OPENINGS INTO THE VEHICLE'S INTERIOR, INCLUDING

ENTRY DOORS, ARE ALLOWED IN THE SHADED AREA.

TAIL PIPE

AXLE LOWER

CLEARANCE LINE

APPROACH

ANGLE

M1715-3s

FIGURE 8-3. DEPARTURE ANGLE AND RAMP ANGLE

8-5

Page 73

IGNITION SYSTEM

The ignition system consists of the magneto assembly, ignition coil, spark plug and ignition wiring. If a problem with the ignition system is suspected, the spark plug can be inspected and an ignition spark check can be made without removing the genset from the vehicle. Perform the spark plug, ignition coil and ignition wiring checks before proceeding to the Magneto Assembly section.

WARNING

Electrical shock can cause severe personal injury or death. Do not touch electrical wiring or components during testing. Disconnect electrical power by removing the starting battery negative (–) cable before handling electrical wiring or components. Do not connect meters while circuit is energized. Use rubber insulative mats placed on dry wood platforms over floors that are metal or concrete when testing electrical equipment. Do not wear jewelry or damp clothing (particularly wet shoes) or allow skin surfaces to be damp when handling electrical equipment.

Spark Plug (E2)

Remove the spark plug and inspect the electrode. If the spark plug has carbon deposits, use a wire brush to clean it. If the spark plug is badly fouled or deformed, replace it. Measure and reset the spark plug gap as shown in Figure 8-4. See Section

Specifications

. An examination of the spark plug can often help diagnose an engine problem. Refer to the following spark plug conditions:

• Carbon Fouled – Check for a poor high tension lead connection, faulty choke operation, rich fuel mixture or dirty air filter.

If the spark plug is in good condition, proceed to the

Ignition Coil

section, following.

Ignition Coil (T1)

The ignition coil is a transformer that steps up the magneto output voltage to about 20,000 volts for spark plug firing. The coil consists of a primary and a secondary winding. Perform the following checks:

WARNING

mable, and can result in severe personal injury or death if ignited. Make certain that no gasoline or other flammable fumes are present. Park the vehicle in a well-ventilated area, and leave the genset compartment door open for several minutes before performing this test.

Ignition Spark Check:

tion system components and wiring.

1. Make sure the engine oil level is adequate and that the genset is level.

2. Remove the spark plug, reconnect the spark plug lead and ground the plug side electrode to bare metal on the engine.

3. Do not touch the plug or plug wire during testing. Crank the engine and observe the plug. If a good spark is observed, the ignition system is good. If no spark, or a weak spark is observed, proceed to the coil winding check.

Gasoline vapor is extremely flam-

This checks all of the igni-

SPARK PLUG GAP

(SEE SECTION 2. SPECIFICATIONS)

• Oil Fouled – Check for low compression.

• Burned or Overheated – Check for leaking in-

take manifold gasket, lean fuel mixture or incorrect spark plug type.

• Splash Fouled – Check for accumulated combustion chamber deposits. See

Push Rods and Cylinder Head

Rocker Arms,

section on Page

10-3.

• Light Tan or Gray Deposits – Normal plug color.

ES1374s

FIGURE 8-4. MEASURING PLUG GAP

8-6

Page 74

Ignition Coil Ohmmeter Check:

Remove the control panel mounting screw (Torx T-30) to access the ignition coil. Check the ground lead for continuity between the ground lead terminal and a clean ground point on the intake manifold.

Disconnect the spark plug lead from the spark plug and disconnect the primary lead from the terminal on the coil. Remove the ignition coil mounting screws and remove the ignition coil from the genset for testing. See Figure 8-5.

1. Inspect the terminal and leads for signs of corrosion or looseness and look for cracks or other damage. Look for evidence of electrical leakage around the high tension connection (indicated by carbon tracking). Replace a coil with any defects.

2. Measure the primary winding resistance. Connect one ohmmeter lead to the primary terminal and the other lead to the ground lead ring terminal. The resistance should be approximately

0.5 ohms at 75

°F (24°C). Replace the coil if a

high or low reading is measured.

3. Measure the secondary winding resistance. Connect one ohmmeter lead to the spark plug connector, inside the boot, and the other lead to the ground lead ring terminal. The resistance should be approximately 1,100 ohms at 75°F (24

°C). Replace the coil if a high or low reading

is measured.

If the coil windings check good, proceed to the Ignition Wiring check.

Ignition Wiring

The ignition wiring consists of the following:

• One wire from the magneto to the ignition coil primary.

• One ignition enable wire from the control assembly to the magneto.

• One wire from the low oil level switch to the control assembly. (Spec A-F only, if applicable.)

• One high tension lead from the ignition coil secondary to the spark plug.

Refer to the figure in Section

Diagram

that corresponds to your particular genset.

12. Wiring Schematic/

(Do not disassemble the genset to check the magneto wiring at this time.)

Thoroughly inspect the ignition wiring for loose connections and cuts or breaks in the insulation. Test suspect leads for continuity with an ohmmeter. Use a megger to check for breaks in the spark plug lead. Also check control wiring for loose or grounded connections. If any problems are found, correct them and repeat the ignition spark check. If no problems are found proceed to the

Magneto Assembly

sec-

tion, following.

SPARK PLUG BOOT

(SECONDARY)

GROUND LEAD

PRIMARY

TERMINAL

• One ground wire connected to the ignition coil and one ground wire connected to the magneto assembly.

ES1767-1s

FIGURE 8-5. IGNITION COIL

8-7

Page 75

Magneto Assembly (G2)

The magneto assembly is a noncontact capacitive discharge (breakerless) type that is mounted to the generator endbell. As the engine cranks, two permanent magnets on the fan hub assembly pass very close to the magneto inducing a voltage in two coils in the magneto. One coil charges a capacitor that discharges a voltage to the coil when triggered. The other coil powers the circuit that triggers the charge circuit. The discharge voltage from the magneto (approximately 16 to 60 VAC when measured with a digital voltmeter) is supplied to the primary of the ignition coil.

If no spark was seen in the

Ignition Spark Check

Page 8-6 and all accessible ignition wiring checks good, perform the

Magneto Assembly Check:

Magneto Assembly Check,

Use a known good

(new) ignition coil.

1. Make sure the cranking circuit and battery are

in good condition.

2. Disconnect the low oil level shut down circuit.

Locate the lead from the low oil level switch that comes out of the top the oil base below the spark plug. Separate the in-line quick connect where lead S2 J1-7 connects to the low oil level switch.

3. Remove the spark plug, reconnect the spark

plug lead and ground the plug side electrode to bare metal on the engine.

4. Do not touch the plug or plug wire during test-

ing. Crank the engine and observe the plug. A good spark should be observed. If no spark is observed, the magneto or wires connected to the magneto are the most likely cause. Refer to Section

9. Generator

for generator disassem-

bly to access the magneto assembly.

burned in the combustion chamber. A stuck or damaged breather valve can cause oil leaks, high oil consumption, rough idle, reduced engine power, and a rapid formation of sludge and varnish within the engine.

Crankcase Breather Service Procedure

Oil leaks at the seals may indicate that the crankcase is pressurized. Use the following procedure to eliminate this condition.

1. Remove the breather tube from the valve cover (see Figure 8-6).

2. Remove the head cover and breather assembly.

3. Inspect the reed valve. It must be flat with no

signs of creases or other damage. Replace a defective reed valve. If the breather is dirty, clean it in parts cleaning solvent.

4. Check the breather tube and air passages for clogging and clean as required.

WARNING

Most parts cleaning solvents are flammable and can result in severe personal injury if used improperly. Follow the solvent manufacturer’s recommendations when cleaning parts.

BREATHER HOSE

REED

VALVE

CRANKCASE VENTILATION SYSTEM

The crankcase breather prevents pressure from building up in the crankcase. It also prevents oil contamination by removing moisture, gasoline vapors and other harmful blow-by materials from the crankcase. These vapors are routed to the carburetor where they are mixed with the incoming air and

LS1173-1s

FIGURE 8-6. CRANKCASE BREATHER SYSTEM

8-8

Page 76

GOVERNOR

The governor controls engine speed, which directly affects the frequency and voltage output of the generator. The governor reacts to the speed/frequency differential between no-load and full-load conditions, known as “droop”. Good overall governor operation requires a proper amount of governor droop. Too large a droop, and genset voltage/frequency control may be adversely affected. Too small a droop may cause erratic governor action or alternately increase and decrease engine speed, “hunting” for the proper speed.

Governor Adjustments

This procedure is used to adjust the governor to bring frequency and voltage within the specified range, and to set governor stability.

WARNING

cause severe personal injury. Keep clothing, hair, jewelry, and fingers clear when adjusting the governor.

WARNING

burns. Always allow the genset to cool before touching any components or removing any parts.

CAUTION

meter and a load bank capable of providing a load of 4000 watts are needed to properly set the governor adjustments.

Equipment required for governor adjustment includes:

• Digital frequency/voltmeter with 0.3% frequency accuracy, 0.5% voltage accuracy. Recommended: Fluke 8060A or 85 series

• Digital ammeter. Recommended: Beckman 4410

• Variable load bank with 4 kW capacity

Connect an accurate voltmeter,ammeter and frequency meter to the generator. A small speed drop, not noticeable without instruments, will cause an objectionable voltage drop.

If a carburetion problem is suspected, make certain that the carburetor is adjusted correctly before at-

Contact with moving parts can

A hot genset can cause severe

An accurate voltmeter, frequency

tempting to adjust the governor (see the

Fuel System

A binding governor shaft, governor linkage, or carburetor throttle will cause hunting. Also a fouled spark plug can cause missing and hunting. Check for these conditions before making governor adjustments.

CAUTION

section on Page 8-11).

Voltage/frequency-sensitive equip-

Gasoline

ment such as VCRs, televisions, computers, etc. may be damaged by power line frequency variations. Some solid-state devices are powered whenever connected to an AC outlet even if the device is not in actual operation. For this reason, disconnect all devices which are voltage or frequency-sensitive before attempting any carburetor/governor adjustments. If disconnecting the devices is not possible, open the circuit breaker(s) at the distribution panel or at the genset, if so equipped.

Adjustments to the governor should be made in the following sequence.

1. Run the genset at least 10 minutes at 50% to 75% of its rated load. Check that the choke is completely open. If the governor is completely out of adjustment, make a preliminary adjustment at no load to attain a safe voltage and speed operating range.

2. Check the governor linkage for binding or excessive looseness. Check the motion spring for bending or damage and straighten or replace as needed.

3. With unit operating at no-load, adjust the speed adjustment screw (see Figure 8-7 on Page 8-10) on the governor linkage to obtain 62 Hz, and 127.5 " 4.5 volts. Set 50 hertz units to obtain 52.0 " 0.5 Hz at between 220 and 231 volts for 220 volt units and 240 to 252 volts for 240 units. To increase the engine speed, turn the adjustment screw clockwise. To decrease the engine speed, turn the adjustment counterclockwise.

4. Check the frequency and voltage first with a load applied and then with no load applied. The frequency and voltage should stay within the limits shown in Table 8-1 on Page 8-10.

5. Adjust the governor sensitivity to give the closest regulation (least speed and voltage differ-

8-9

Page 77

ence between no-load and full-load) without causing a hunting condition. To increase the sensitivity, turn the adjustment screw counterclockwise. To decrease the sensitivity, turn the adjustment screw clockwise.

6. Recheck the speed setting made in step 3 and readjust if necessary.

7. Set the carburetor throttle stop screw as specified in the Fuel System section.

If the governor action is erratic after adjustments are made, loosen the governor arm mounting bolt and rotate the shaft fully clockwise, then retighten the bolt. Reset the governor adjustments and recheck speed and droop. Springs tend to lose their calibrated tension through fatigue after long usage. It may be necessary to put the stationary end of the spring in a different hole to change the tension, or replace the spring altogether. If this does not improve operation, the problem may be within the governor mechanism (see Section

Assembly

10. Engine Block

TABLE 8-1 CHECKING VOLTAGE AND

SPEED/FREQUENCY

60 Hz 50 Hz 50 Hz

1∅, 2Wire 1∅, 2Wire 1∅, 2Wire

120 V 220 V 240 V

Voltage

Maximum NoLoad 126 235 256 (Typical NoLoad) (125) (228) (248) Minimum Full Load 108 205 224 (Typical FullLoad) (118) (215) (236)

Speed/Frequency

Maximum NoLoad Speed (rpm) 3780 3150 3150 Frequency (Hz) 63 52.5 52.5 (Typical Frequency) (62.5) (52) (52)

Minimum FullLoad Speed (rpm) 3570 2940 2940 Frequency (Hz) 59.5 49 49 (Typical Frequency) (59.5  (49.5  (49.5 

60.5) 50.5) 50.5)

GOVERNOR

SHAFT

SPEED

ADJUSTMENT

SCREW

FIGURE 8-7. GOVERNOR ADJUSTMENTS

MOUNTING

BOLT

GOVERNOR

LINKAGE

SENSITIVITY

ADJUSTMENT

SCREW

GOVERNOR

ARM

8-10

Page 78

GASOLINE FUEL SYSTEM

The fuel system must be properly adjusted and in good condition for efficient genset operation. The main components of the fuel system include:

SPEC A MODELS

AIR FILTER

• Air filter

• Air preheater

• Choke

• Carburetor

• Intake manifold

• Fuel filter

• Fuel pump

Air Filter and Preheater Assembly

This assembly consists of the air filter housing, air filter, and preheat door assembly. See Figure 8-8.

WARNING

explosion that can cause severe personal injury or death. Eliminate all possible ignition sources such as open flame, sparks, cigarettes, pilot lights, arc-producing equipment, and electrical switches from the work area and rooms with common ventilation, when performing the following procedures.

The air filter can be serviced without removing the genset from the vehicle. Remove the service access cover and the air filter housing/cover. Remove the air filter. If the air filter is dirty, replace it.

Spec A:

side the air filter housing. Inspection of the preheater door operation can be made at this point.

Fuel presents the hazard of fire or

The preheat door assembly is located in-

HOUSING

FS1866s

FOAM BLOCK

(60 HZ ONLY)

WING NUTS

BEGIN SPEC B MODELS

PREHEAT

DOOR

TOP OF

HOUSING

PREHEAT

DOOR

ROUND AIR INLET OPENING

TOP OF

HOUSING

Spec B:

The preheat door assembly is located inside the air housing assembly. If a problem with the preheat door assembly is suspected, refer to Sec-

9. Generator

tion

for details on removing the air

housing assembly.

The preheater door should be fully open at 70°F (21°C) and should align with the top of the housing. Rotate the door down over the round air inlet opening in the housing, then release it. The door should move freely back to the open position. If the door does not move freely, clean the spring and housing with low pressure compressed air and retest.

8-11

AIR FILTER

FILTER

HOUSING

M18967

FIGURE 8-8. AIR FILTER AND PREHEATER

COVER

ASSEMBLY

COVER

Page 79

Carburetor and Intake Manifold Assembly

This assembly consists of the carburetor and the intake manifold assembly. See Figure 8-9. It is easier to disconnect the carburetor linkages if the genset housing is removed.

WARNING

Disassembly:

move the carburetor and intake manifold assembly.

1. Disconnect the fuel line and plug it to prevent fuel spill and fuel vapor accumulation. (Begin Spec B models: Disconnect the fuel solenoid leads.)

2. Remove the air filter assembly.

Fuel presents the hazard of fire or

Use the following procedures to re-

3. Remove the carburetor mounting screws from the left side of the endbell.

4. Close the choke and throttle plates by rotating their shafts in a counterclockwise direction. Pull the carburetor with its gaskets out slowly.

5. Disengage the governor and choke linkages from the carburetor (it may be necessary to remove the automatic choke assembly mounting screw to remove its linkage).

6. Remove the intake manifold mounting nuts and lift off the manifold. Remove the intake manifold gasket and plug the intake port with a rag to prevent loose parts from accidentally entering the port.

Assembly:

Perform the assembly steps in reverse order of disassembly. Use new gaskets between the intake manifold and the engine, between the intake manifold and the carburetor, and between the carburetor and the air cleaner adapter. Do not use sealer on the gaskets. Tighten the intake manifold capscrews to the specified torque.

AIR FILTER MOUNTING

ASSEMBLY

FIGURE 8-9. CARBURETOR AND INTAKE MANIFOLD ASSEMBLY

CARBURETOR

ASSEMBLY

INTAKE

ELBOW

8-12

Page 80

Carburetor Replacement (Beginning Spec D)

Other than turning the altitude adjust knob shown in Figure 8-10 (which changes the main fuel mixture within a limited range), fuel mixture adjustments should not be attempted. Nor should the carburetor be overhauled. Instead, a malfunctioning carburetor should be replaced. Before replacing a carburetor, however, make certain that:

• All other necessary engine and generator adjustments and repairs have been performed.

• The carburetor is actually malfunctioning, by carefully following the troubleshooting procedures in Section

6. Troubleshooting

See the instructions on how to remove and replace the carburetor under the subheadings

Preheater Assembly and Intake Manifold Assembly

on Page 8-11 and

on Page 8-12.

A throttle stop screw is provided for adjusting the “closed” position of the throttle plate to obtain proper governor response when loads are being disconnected. (See

Governor Adjustments

To adjust the throttle stop screw:

1. Connect a frequency meter and start and run the genset until it has warmed up to normal operating temperature.

2. Disconnect all loads. Pull the governor linkage toward the front of the genset so that the tang on the throttle lever bears against the throttle stop screw. Adjust the stop screw to obtain a frequency of 54 to 56 Hz on 60 Hz gensets (44 to 46 Hz on 50 Hz gensets).

Air Filter and

Carburetor

on Page 8-9)

CHOKE

LEVER

ALTITUDE

SCALE

ALTITUDE

ADJUST

KNOB

FIGURE 8-10. CARBURETOR ADJUSTMENTS

(BEGINNING SPEC D)

THROTTLE

STOP SCREW

THROTTLE

LEVER

TAMPER

RESISTANT

PLUG OVER

IDLE MIXTURE

NEEDLE

FUEL

SHUTOFF

SOLENOID

(E3)

8-13

Page 81

Carburetor Mixture Screw Adjustments (Does Not Apply to Spec D and Later)

The most common causes of poor carburetion are the idle and main mixture screws being out of adjustment and contamination in the carburetor. Variation from the correct mixture settings can cause serious engine problems. Too rich a mixture wastes fuel and increases engine wear by washing the lubricant from the cylinder walls and diluting the crankcase oil. Too lean a mixture causes power loss, flat spots in acceleration, and a tendency to burn valves and spark plugs.

Unless a carburetion problem is indicated, the mixture screw settings should not be changed. This does not include problems due to high altitude, which can usually be corrected with a small adjustment of the main mixture screw within the range provided by the limiter cap. The limiter cap on the main mixture screw should not be removed unless the carburetor has been overhauled or is way out of adjustment. Before making adjustments, make sure the ignition system is working properly.

CAUTION

screws tight will damage the needle and seat. Turn in ONLY until light resistance can be felt.

To make preliminary mixture screw settings:

Remove the limiter cap from the main adjustment screw. Turn both of the mixture screws in until lightly seated (Figure 8-11), then turn the main screw out 2 turns and the idle screw out 2-1/2 turns.

Forcing the mixture adjustment

3. Turn the main adjustment screw inward until voltage or frequency drop and then outward until voltage or frequency drop again. Locate the point where voltage and frequency are the highest. From this point turn the main adjustment screw out an additional 1/4 turn. Install the limiter cap so it is vertical.

4. Remove the load and verify that the frequency is within 62.5 " 0.5 Hz on 60 Hz models or 52 " 0.5 Hz on 50 Hz models. Adjust the governor speed adjustment screw if necessary to obtain required frequency.

5. Turn the idle adjust screw inward until voltage and frequency drop and the engine begins to run rough or hunt. Back the idle screw out until the engine runs smooth without hunting.

6. Pull the governor linkage toward the front of the genset so that the throttle lever on the carburetor is resting against the throttle stop screw (Figure 8-11). Adjust the stop screw to obtain a setting of 55 " 1 Hz (45 " 1 Hz on 50 Hz units).

7. Readjust the governor speed screw to within

62.5 " 0.5 Hz on 60 Hz models or 52 " 0.5 Hz on 50 Hz models at no-load. Observe the sensitivity of the genset. If necessary, adjust the governor sensitivity as specified in

Governor

on Page 8-9.

THROTTLE

STOP SCREW

CAUTION

A hot genset can cause severe burns. Always allow the genset to cool before touching any components or removing any parts.

Start the engine and allow it to run for ten minutes. Use the following procedure to adjust the mixture screws:

1. Stop the genset and connect a voltmeter, frequency meter and load bank to the generator output leads.

2. Start the genset and apply the rated load. Verify that the frequency is within 60.5 " 1 Hz. Adjust the governor speed adjustment screw if necessary to obtain the required frequency.

8-14

IDLE

ADJUSTMENT

SCREW

LIMITER

CAP

MAIN

ADJUSTMENT

SCREW

FIGURE 8-11. MIXTURE SCREW ADJUSTMENT

(PRIOR TO SPEC D)

FS1807-2s

Page 82

Carburetor Overhaul (Does Not Apply to Spec D and Later)

3. Slide the float pin out of the float passage. Remove the float and float valve.

Carburetion problems that cannot be corrected by mixture screw adjustments are usually a result of gummed-up fuel passages or worn internal parts. The most effective remedy is a complete carburetor overhaul.

Overhauling a carburetor consists of complete disassembly, a thorough cleaning, and replacement of worn parts. The carburetor repair kit includes new gaskets and replacements for the parts that are most subject to wear.

Carefully note the location of carburetor parts for correct reassembly. Review these instructions before starting. The carburetor components are illustrated in Figure 8-12.

Gasoline fuels deteriorate over time causing fuel system corrosion and the formation of gum and varnish-like deposits. If the genset will not be operated for more than 120 days, a fuel preservative and sta-

bilizer such as OnaFresh

should be used to pro-

tect the fuel system. Follow the label instructions for using a fuel additive.

NOTE: The throttle plate screws are secured with epoxy. Do not remove the choke or throttle plates, shafts, arms or governor link bushing unless they are defective.

THROTTLE

STOP

SCREW

IDLE MIXTURE ADJUSTMENT

SCREW

FLOAT VALVE

FLOAT

GASKET

WARNING

Gasoline is extremely flammable. Severe personal injury or death can result if it is ignited. Eliminate all possible sources of ignition including fire, flame, spark, pilot light, cigarettes, arc-producing equipment, electrical switch, or other ignition sources before performing this procedure.

Removal and Disassembly:

Remove the carbure-

tor and intake manifold assembly, as specified in the

Carburetor and Intake Manifold Assembly

on Page 8-12. Remove the carburetor from the intake manifold. Carburetor parts are fragile and they must be handled with care. Never force a part when disassembling or assembling. Disassemble the carburetor as follows:

1. Remove the main and idle mixture screws.

2. Separate the lower section of the carburetor. Remove the float chamber and gasket by removing the chamber set plug.

OnaFresh is a trademark of Onan Corporation.

FLOAT

CHAMBER

ADJUSTMENT

WASHER

CHAMBER SET PLUG

SPEC A

MODELS

ONLY

FIGURE 8-12. CARBURETOR OVERHAUL

(PRIOR TO SPEC D)

LIMITER

CAP

FUEL SHUTOFF

SOLENOID (E3)

BEGIN SPEC B

MODELS

MAIN

SCREW

FS1807-1s

8-15

Page 83

Cleaning and Repair Procedure:

1. Soak all metal components to be reused in carburetor cleaner. Do not soak rubber or plastic parts or they will be damaged. Follow the instructions on the cleaner container.

WARNING

Most parts cleaning solvents are flammable and can result in severe personal injury if used improperly. Follow the manufacturer’s recommendations when cleaning parts.

CAUTION

Forcing the mixture adjustment screws tight will damage the needle and seat. Turn them in until only light tension can be felt.

4. Adjust the idle and main mixture screws as described in this section.

2. Remove the carbon from the carburetor bore, especially where the throttle and choke plates seat. Be certain not to plug the idle or main fuel ports.

3. Blow out all passages with compressed air. Do not use wire or any cleaning utensil that might widen critical passages. Wear goggles while performing this procedure.

4. Examine any needle valves not included in the repair kit, and replace if damaged (Figure 8-13). Replace the float if it is damaged or contains fuel.

5. Check the choke and throttle shafts for excessive play in their bore. Replace them if necessary.

6. Replace old components with the new parts from the repair kit.

Carburetor Reassembly:

1. If removed during overhaul, slide in the throttle shaft and install the throttle plate using new screws (if needed). Center the plate in the throttle bore before tightening the screws. To do this, back the throttle stop screw out as necessary, and close the throttle lever. Seat the plate by gently tapping it with a small screwdriver, then tighten the screws. Install the choke shaft and plate in the same manner.

DAMAGE AND

WEAR OCCUR

HERE

FS1483-4s

FIGURE 8-13. MIXTURE NEEDLE INSPECTION

FLOAT VALVE

FLOAT

2. Screw in the main nozzle. Install the float valve into the slot in the float and install the float with the float pin (Figure 8-14). Make sure that the float moves freely without binding.

3. Install the main mixture screw assembly and the idle mixture screw assembly.

FLOAT

FIGURE 8-14. FLOAT INSTALLATION

8-16

Page 84

Choke Assembly

The genset has an automatic choke assembly that consists of a bimetal choke coil, coil housing, heater tube (from the exhaust tube), and choke linkage. The choke linkage connects to the choke shaft lever on the carburetor.

When the engine is cold, the choke coil position causes the linkage to hold the choke nearly closed. When the engine starts, hot air from the exhaust manifold enters the coil housing. The choke coil expands pulling the linkage to partially open the choke. As the engine warms up, the coil continues to expand and gradually opens the choke and holds it open while the engine is operating. This action varies the fuel/air mixture as the engine warms up to provide smooth engine operation.

If the engine starts but runs rough and exhausts black smoke after a minute or two of operation, the choke setting is too rich. If the engine starts but sputters or stops before it warms up, the choke setting is too lean.

Choke Adjustment:

make sure it is not bent or rubbing. Rotate the choke lever on the carburetor. The choke shaft should move freely and it should return to its original position when released. Inspect the heater hose to make sure it is installed properly and in good condition. Refer to Figure 8-15 on Page 8-18.

Check the choke linkage to

WARNING

The choke housing becomes very hot during operation and can cause severe burns if touched. Allow the genset to cool down before handling the choke assembly.

1. Allow the genset to cool down. The temperature inside the housing must be the same as the ambient temperature.

2. Loosen the adjustment screw holding the adjustment plate.

3. Slowly rotate the adjustment plate until the bimetal choke shaft connection is visible in the sight window. This is the correct setting for an ambient temperature of 70° F (21° C).

If the ambient temperature is higher or lower than 70° F (21° C), make a mark on the choke coil housing opposite the center mark on the adjustment plate. Each mark on the adjustment plate is equal to 10° F (12.2° C) of difference from 70° F (21° C). If it is warmer than 70° F (21° C), rotate the plate clockwise. If the temperature is less than 70° F (21° C), rotate the plate counterclockwise. Tighten the adjustment screw.

Example:

(32° C), rotate the adjustment plate two marks clockwise from the 70° F (21° C) position marked on the housing.

4. Move the choke lever back and forth to check for free movement. Verify that the choke does not bind or stick.

If the ambient temperature is 90° F

8-17

Page 85

CHOKE LINKAGE

FIGURE 8-15. CHOKE ASSEMBLY

CHOKE COIL

HOUSING

SIGHT

WINDOW

ADJUSTMENT

SCREW

ADJUSTMENT

PLATE

FS1867s

Bimetal Coil Replacement:

After making the choke adjustment, start the genset and observe engine operation. If the choke does not open properly, replace the bimetal coil in the choke housing as follows. Refer to Figure 8-15.

1. Remove the adjustment screw and washer from the choke coil housing.

2. Remove the housing. Straighten the tab from

the adjustment plate to release the bimetal coil.

3. Remove choke linkage from the bimetal coil and install linkage on the new coil.

4. Assemble the new coil to the adjustment plate and bend the tab on the adjustment plate to secure coil.

5. Install choke coil housing and secure with screw and washer. Perform the choke adjustment procedure.

8-18

Page 86

Fuel Filter

Change the fuel filter at the interval recommended in the Operator’s Manual, or if performance problems occur and bad fuel is suspected.

WARNING

explosion that can cause severe personal injury or death. Do not permit any flame, spark, pilot light, cigarette, arc-producing equipment, electrical switch, or other ignition source near the fuel system. Keep a type ABC fire extinguisher nearby.

1. Close the fuel supply valve (if equipped) or remove the fuel line from the fuel filter. Plug the end of the fuel line to prevent fuel leakage and vapor accumulation. See Figure 8-16.

2. Run the genset until it runs out of fuel. Allow the genset to cool down before replacing the fuel filter.

3. Use a deep 11/16-inch socket to unscrew the filter from the fuel pump.

4. Install a new fuel filter and tighten it securely to prevent fuel leakage.

5. Connect the fuel line to the new filter. Open the fuel valve (If equipped). Start the genset and check for fuel leaks. Repair any leaks immediately.

Fuel presents the hazard of fire or

WARNING

Fuel presents the hazard of fire or explosion that can cause severe personal injury or death. Do not permit any flame, spark, pilot light, cigarette, arc-producing equipment, electrical switch, or other ignition source near the fuel system. Keep a type ABC fire extinguisher nearby.

Fuel Pump Test:

Test the fuel pump by checking

the fuel pump outlet pressure as follows:

1. Make sure the fuel tank has sufficient fuel to supply the genset. The genset fuel pick-up tube ends well above the bottom of the vehicle fuel tank. The genset can be out of fuel even when the tank is partly full.

CAUTION

Incorrect replacement of service parts can result in damage to equipment. Use genuine Onan replacement fuel filter only.

Fuel Pump

An electric fuel pump is used to supply fuel to the carburetor. If the pump malfunctions or if insufficient fuel delivery is suspected, use the following procedures to test the fuel pump.

WARNING

electric fuel pump for the Onan-supplied fuel pump. The output pressure from an automotive pump is much higher and can cause carburetor flooding or fuel leakage, creating a fire hazard.

Do not substitute an automotive

FUEL FILTER

FUEL PUMP

FS1868-1s

FIGURE 8-16. FUEL FILTER REPLACEMENT

8-19

Page 87

2. Check the the genset starting battery voltage when cranking and running the genset. Measure battery voltage between the brown lead and ground (Figure 8-17). The pump will not work properly if the cranking or running voltage is less than 6 VDC.

If the battery voltage is low, charge the battery and retest.

3. Remove the fuel line from the carburetor inlet and install a pressure gauge.

4. Press the Start switch and hold it for several seconds, until the pressure reading stabilizes.

5. The pressure reading should be 3.25 psi (22.4 kPa) to 4 psi (27.5 kPa). The pressure should hold constant or drop off very slowly.

If the pressure reading is below 3.25 psi (22.4 kPa), tap the pump body with a screw driver handle to free the piston from fuel deposits. If the pump still does not work and the battery voltage is adequate, replace fuel pump with an Onan-supplied pump.

If the pressure is higher than 4 psi (27.5 kPa), fuel can overcome the needle and float assembly and cause flooding. A negative fuel supply line pressure (more than minus 1.3 psi or three feet of lift) will prevent the pump from delivering enough fuel. Measure the pressure at the pump inlet. Inlet pump pressure must be between a minus 1.3 psi and a positive 1.5 psi (minus 8.3 kPa and positive 10.3 kPa). If an abnormally high or low inlet pressure is measured the fuel line installation is improper. Refer to the Manual.

Fuel System

section of the Installation

8-20

Page 88

PRESSURE GAUGE

FUEL PUMP

FIGURE 8-17. FUEL PUMP TEST

FS1868s

8-21

Page 89

LPG FUEL SYSTEM

WARNING

and can cause asphyxiation. NFPA 58, Section

1.6 requires all persons handling LPG to be trained in proper handling and operating procedures.

LPG is flammable and explosive

See the instructions on how to remove and replace the carburetor under the subheadings

Preheater Assembly and Intake Manifold Assembly

on Page 8-11 and

on Page 8-12. Refer-

Air Filter and

Carburetor

ences to preheaters and chokes are not applicable to LPG carburetors.

Do not smoke if you smell gas or are near LPG containers or LPG-burning equipment or are in an area sharing ventilation with such equipment. Keep flames, sparks, pilot lights, electrical arcs, arc-producing equipment, electrical switches and all other sources of ignition well away. Have an ABC fire extinguisher handy.

LPG models are designed for a low-pressure vaporwithdrawal type of LPG supply system.

LPG supply pressure at the inlet to the demand regulator must be 9 to 13 inches (229 to 330 mm) water column (WC) when the genset is running under full load.

The components of the genset LPG system include:

• A fuel-shutoff solenoid valve

• A demand regulator with a built-in automatic

priming solenoid which allows fuel to pass through during cranking

• An LPG carburetor and air filter

Before servicing the LPG fuel system, check to see that the LPG container(s) is at least half full. The problem may be that there is not enough LPG to provide the rate of vaporization necessary to meet genset demand, especially on cold days and/or when the genset is under full load.

Carefully follow the instructions for disconnecting the LPG fuel line from the genset under

ing Set from Vehicle Systems

on Page 5-4.

Disconnect-

Demand Regulator with Automatic Priming Solenoid

See Figure 8-18. The demand regulator assembly supplies fuel to the carburetor. It is usually not the cause of fuel system problems. All other possible causes should be checked out before adjusting or replacing the demand regulator assembly.

INLET HOSE

FITTING

AUTOMATIC

PRIMING

SOLENOID

VENT

HOSE

FITTING

OUTLET HOSE

FITTING

WARNING

LPG “sinks” and can accumulate in explosive concentrations. Before disconnecting the LPG fuel line, close the fuel shutoff valve(s) at the LPG container(s) and move the vehicle outside and away from pits or basements or other below-grade spaces where LPG could accumulate.

LOCK-OFF ADJUSTMENT SCREW

(Beginning Spec E, this screw is neither

visible nor accessible for adjustment)

FIGURE 8-18. TOP VIEW OF DEMAND REGULATOR

WITH AUTOMATIC PRIMING SOLENOID

8-22

Page 90

Checking and Adjusting Regulator Lock-off Pressure:

Lock-off pressure is determined as follows by pressurizing the back (vent) side of the regulator diaphragm to simulate carburetor venturi vacuum:

1. Connect the regulator inlet (Figure 8-18 on Page 8-22) to a source of air pressure regulated to 11 inches WC (280 mm WC).

2. Disconnect from the carburetor the LPG supply hose, which comes from the regulator.

3. “T” in two hoses to the end of the hose connected to the regulator vent fitting (3/8 inch I. D.). Use one hose to measure pressure by connecting it to an inclined manometer that reads 0 to 2 inches WC (0 to 50 mm WC) and the other to provide the test pressure.

4. Attach a soap bubble to the end of the LPG supply hose which was disconnected from the carburetor. While reading the pressure indicated by the manometer and watching the soap bubble, blow lightly into the hose being used to pressurize the regulator. Regulator lock-off pressure is the minimum pressure that will cause air to flow through the regulator, as indicated by the expanding soap bubble. (At first the soap bubble may expand due to diaphragm movement but will stop expanding if air is not flowing through the regulator.)

the adjusting screw locknut and test lockoff pressure again. Repeat the procedure if necessary.

• If the lock-off pressure is less than 0.10 inches WC (2.5 mm WC), loosen the lock nut on the lock-off adjusting screw and turn in the screw (clockwise) until the lock-off pressure falls between 0.10 and 0.30 inches WC (2.5 and 7.6 mm WC). Set the adjusting screw locknut and test lock-off pressure again. Repeat the procedure if necessary.

• Replace the demand regulator if it continues to leak after lock-off pressure adjustments have been attempted.

Priming Solenoid Test:

Upon completing the lockoff pressure test, energize the priming solenoid by connecting battery positive (+) to the orange lead and battery negative (–) to the green lead. Replace the regulator assembly if the priming solenoid does not cause the regulator to open.

Priming Solenoid Adjustment:

See Figure 8-19. If the genset does not start when it is hot, rotate the dial counterclockwise—the fuel mixture could be too rich. If the genset does not start when it is at ambient temperature, rotate the dial clockwise—the fuel mixture could be too lean.

CAUTION

If this is a bench test of the regulator, make sure the diaphragm is in a vertical plane (as in the genset), otherwise the weight of the diaphragm will cause erroneous readings of lock-off pressure.

•

For Gensets Beginning Spec E:

Replace the demand regulator assembly if the lock-off pressure does not fall between 0.10 and 0.30 inches WC (2.5 and 7.6 mm WC).

•

For Gensets Prior to Spec E:

Adjust lock-off

pressure as follows:

• If the lock-off pressure is greater than 0.30 inches (7.6 mm) WC, loosen the lock nut on the lock-off adjusting screw and back out the screw (counterclockwise) until the lock-off pressure falls between 0.10 and

0.30 inches WC (2.5 and 7.6 mm WC). Set

METAL DISK RED PLASTIC

DIAL

Adjust the primer solenoid by holding on to the metal disk and rotating the red dial. Turn the dial clockwise to obtain a richer mixture and counterclockwise to obtain a leaner mixture.

FIGURE 8-19. AUTOMATIC PRIMING SOLENOID

8-23

Page 91

Fuel-Shutoff Solenoid Valve

Leak Test:

See Figure 8-20. If there is a smell of gas when the genset is not running, or any other reason to suspect that the valve is leaking, connect the inlet of the valve to a source of air pressure regulated to not more than 14 inches WC (356 mm WC) and disconnect the outlet hose. Replace the solenoid if it leaks, as checked by a soap bubble.

Operation Test:

start (first see Section

If the genset cranks, but does not

6. Troubleshooting

), determine whether or not the valve is opening. With the source of air still connected, energize the valve by connecting battery positive (+) to the top terminal and battery negative (–) to the grounded terminal. Replace the solenoid valve if it does not open when it is energized.

LPG Carburetor (Beginning Spec E)

See Figure 8-21. An LPG carburetor is not likely to cause problems and should be replaced only after all other causes have been eliminated (see Section

6. Troubleshooting

fuel mixture. These carburetors are calibrated at the factory and the adjustments are sealed.

). It is not necessary to adjust

FIGURE 8-20. FUEL SOLENOID VALVE

THROTTLE

LEVER

THROTTLE

STOP SCREW

A throttle stop screw is provided for adjusting the “closed” position of the throttle plate to obtain proper governor response when loads are being disconnected. (See

Governor Adjustments

on Page 8-9)

To adjust the throttle stop screw:

1. Connect a frequency meter and start and run the genset until it has warmed up to normal operating temperature.

2. Disconnect all loads. Pull the governor linkage toward the front of the genset so that the tang on the throttle lever bears against the throttle stop screw. Adjust the stop screw to obtain a frequency of 44 to 46 Hz on 60 Hz gensets (36 to 38 Hz on 50 Hz gensets).

GAS HOSE

FITTING

FIGURE 8-21. LPG CARBURETOR

(BEGINNING SPEC E)

8-24

Page 92

LPG Carburetor (Prior to Spec E)

See Figure 8-22. LPG carburetors prior to Spec E have two adjustment screws that must be properly set for satisfactory operation. The throttle stop screw controls how much the throttle plate remains open when the governor closes the throttle The main adjustment screw controls the fuel mixture. No other adjustments are required with an LPG carburetor since there are no float or choke adjustments.

Mixture Screw Adjustment:

should not be adjusted until the ignition system, governor, and other fuel system components have been checked for correct operation. If the carburetor is totally out of adjustment, turn the mixture screw in until lightly seated. For a preliminary adjustment turn the screw out 2 turns.

CAUTION

Forcing the mixture adjustment screw tight will damage the needle and seat. Turn in only until light resistance can be felt.

Start the engine and allow it to run for about 15 minutes at half load. Figure 8-22 shows the location of the adjustment screw. Use the following procedure to adjust:

The mixture screw

tor is resting against the throttle stop screw. Adjust the stop screw to obtain a setting of 55 " 1 Hz (45 " 1 Hz on 50 Hz units).

6. Release the governor linkage and observe the stability of the genset. Set the voltage and frequency and adjust the sensitivity of the governor as specified under

Governor

on Page 8-9. Add and remove a half load several times to make certain the genset does not bog down or hunt.

Carburetor problems not corrected by the adjustments may be caused by dirt in fuel passages or worn internal parts. Under normal conditions, the carburetor should seldom require cleaning since LP-gas vaporizes completely before reaching the carburetor and leaves no residue. However, a bad fuel supply may allow dirt or oil to collect in the carburetor. This may require carburetor cleaning to restore satisfactory operation.

Cleaning the carburetor includes complete disassembly, thoroughly cleaning, and replacement of parts and gaskets.

1. Stop the genset and connect a voltmeter, frequency meter, and load bank to the generator output leads.

2. Start the genset and apply full rated load. Verify that the frequency is within 60 " 0.5 Hz (50 " 1 on 50 Hz units) and adjust the governor speed adjustment nut if necessary to obtain required frequency.

3. Turn the main adjustment screw inward until voltage or frequency drops and then outward until voltage or frequency drops again. Set the main adjustment screw at the point where the voltage and frequency are highest. If a CO meter is available, follow the manufacturer’s instructions for use and adjust the main adjustment screw to obtain 1 to 2 percent CO.

4. Remove the load and verify that frequency is within 62.5 " 0.5 Hz (52 " 0.5 on 50 Hz units). Adjust governor speed adjustment nut if necessary to obtain required frequency.

5. Pull the governor linkage toward the front of the genset so that the throttle lever on the carbure-

THROTTLE

STOP SCREW

MAIN ADJUSTMENT

SCREW

FIGURE 8-22. LPG CARBURETOR ADJUSTMENTS

(PRIOR TO SPEC E)

8-25

Page 93

ELECTRIC STARTER

A 12-volt electric starter with a negative ground is used for cranking the genset. When the starter is energized, an inertial engagement system causes the starter pinion gear to engage the ring gear on the fan hub assembly. As the starter spins, the starter pinion gear drives the ring gear causing the genset to crank.

Starter Voltage Check

Before removing the starter for service, perform the following starter check to make sure the starter is getting voltage from the control circuit.

1. Connect a voltmeter between the output terminal on the start relay (opposite the BAT terminal with the starter motor lead connected) and ground. See Figure 8-23.

2. Press the start switch and observe the meter reading. If approximately 12 VDC is measured and the starter does not crank, the starter is defective. Proceed to the starter disassembly

section. If low or no voltage is measured check the starting battery, start solenoid, and control wiring.

START RELAY

ES2016

FIGURE 8-23. STARTER VOLTAGE CHECK

8-26

Page 94

Starter Disassembly

The genset must be removed from the vehicle before the starter can be serviced. See Section

paring for Service.

1. Disconnect the genset starting battery cables. Disconnect the negative (–) cable first, to reduce the risk of arcing.

2. Remove the genset outer housing. Disconnect the positive (+) cable from the starter lug terminal.

3. Remove the rear mounting nut from the starter.

5. Pre-

Remove the engine bracket behind the starter from the engine (Torx T-30) and muffler.

4. Remove the starter mounting nuts (bolts on Spec A). Carefully disengage the starter from the end bell.

5. Use a 1/8 to 5/32 inch nail set to remove the roll pin from the armature shaft. (When reassembling, use a new roll pin.) Remove the return spring, gear and clutch assembly as required. See Figure 8-24.

6. Remove the starter through-bolts. Carefully separate the brush end cap housing from the armature assembly.

ROLL PIN

SPRING

RETAINER

SUPPORT PLASTIC RETAINER WITH

A VISE OR OTHER SOLID SURFACE

USE CARE NOT TO HAVE SPRING

RETURN “LEG” BETWEEN THE

PLASTIC RETAINER & SUPPORT

WHEN DRIVING OUT ROLL PIN.

FIGURE 8-24. DRIVING ROLL PIN OUT OF STARTER ASSEMBLY

STARTER

5/32“ TO 1/8“ NAIL SET

SOLID

SUPPORT

STARTER

POSITIVE (+)

TERMINAL

STARTER

THROUGH BOLTS

ES1608s

ES1609-1s

8-27

Page 95

Testing Armature for Grounds

Touch one ohmmeter lead to a commutator bar, touch the other lead to the armature shaft and the core laminations. A low resistance reading indicates a grounded armature. Replace a grounded armature with a new one. See Figure 8-25.

Testing Armature for Shorts

Use a growler (Figure 8-26) to locate shorts in the armature. Place the armature in the growler and hold a thin steel blade (hacksaw blade) parallel to the core and just above the armature, while slowly rotating the armature in the growler. A shorted armature will cause the blade to vibrate and be attracted to the core. Replace a shorted armature with a new one.

Testing Armature for Opens

Touch one ohmmeter lead to a commutator bar, then touch the other lead to each of the other commutator bars in turn. A high resistance indicates an open circuit between the commutator bars and armature windings. Replace an open armature with a new one.

COMMUTATOR

BARS

ES1614s

FIGURE 8-25. TESTING ARMATURE FOR

GROUNDS

HACKSAW BLADE

Brush Inspection

Measure brushes (Figure 8-27) and replace them if worn to less than 0.315” (8 mm).

GROWLER

ES1615s

FIGURE 8-26. TESTING ARMATURE FOR SHORTS

0.315 INCH (8 MM)

WEAR LIMIT

FIGURE 8-27. BRUSH INSPECTION

NEW 0.472 INCH

(12 MM)

8-28

Page 96

Starter Re-assembly

Use this procedure to return the electric starter assembly to service.

1. Wipe all of the dirt and oil from the starter components with a clean cloth. Blow off dust with filtered low-pressure compressed air.

CAUTION

the starter. Do not immerse bearings in cleaning fluid. Use a brush dipped in clean engine oil to remove dirt from bearings. Avoid getting oil on brushes or commutator.

2. Push the negative brush terminals over the through-bolt holes on the brush endcap (Figure 8-28).

3. Insert the positive brush stud into the hole, and torque to 25-30 lb-in. (2.83 - 3.39 Nm).

Oil on the armature will damage

4. Insert the brush springs into brush holders. Insert the brush tabs into the spring ends and slide brushes into brush holders in endcap. Make sure all brush wires are facing up.

5. Place a washer on the commutator end of the shaft, then put the armature into the brush endcap. Push the four brushes toward the commutator, make sure that the springs are correctly positioned on the brushes.

NOTE: Replacement brushes are supplied preassembled in the endcap. Remove the brush retainers after installing armature.

6. Make sure that all brush wires are clear of the commutator, and that uninsulated sections of wires do not touch the inside of the housing, or adjacent brush boxes.

7. Place the magnetic housing over the armature. Hold down the armature and the end cap by pressing a nut driver over the end of the shaft.

TORQUE TO 510 INLBS

POSITIVE

BRUSH

STUD

NEGATIVE BRUSH

TERMINAL

(.571.13 N•M)

TORQUE TO 2530 IN

LBS (2.833.39N•M )

NEGATIVE BRUSH

FIGURE 8-28. BRUSH ENDCAP

IMPORTANT! THIS INSULATED SHUNT MUST

BE ROUTED THROUGH UNINSULATED SHUNT

AS SHOWN TO PREVENT CONTACT WITH

COMMUTATOR IN FINAL ASSEMBLY.

TERMINAL

ES-1612-2s

8-29

Page 97

1. Place a spring washer and a flat washer on the shaft, as shown in Figure 8-29.

2. Place the mounting bracket on the motor with the through-bolt lead-ins to the inside of the motor. The “flat” near one mounting hole should line up with the positive stud on the end cap, so the through-bolts line up.

3. Insert the through-bolts, and torque to 35-45 lbin. (3.96 - 5.09 Nm).

4. Wipe dust from the helix and gear, and apply a light coat of GE Versilube 322-L to the outside diameter of the helix, the inside diameter of the gear and the unchamfered end of the gear. Place the clutch and helix assemblies on the motor shaft, with flats engaged in the clutch hole.

5. If the return spring is unassembled:

A. Place a 1-1/16 inch O.D. washer over the

end of the shaft.

B. With the chamfered side of the shaft hole

facing up, place a plastic retainer on the shaft and line up the hole with a hole in the shaft.

C. Support the plastic retainer with a vise or

other solid surface. Using a 5/32 or 1/8 inch nail set and hammer, drive in a new roll pin. The pin should be driven about 1/10th of an inch (2.5 mm) from the edge of the plastic retainer, or in such a way that it is evenly spaced from each side.

D. Place the spring cover over the top of the

plastic retainer, then place the return spring on top of the retainer.

E. With a washer placed over the point of the

plastic retainer, push the metal retainer into the hole of the plastic retainer as far as it will go.

WASHER

ROLL

METAL SPRING

RETAINER &

WASHER

RETURN

SPRING

RETURN

COVER

CLUTCH & SPLINE

ASSEMBLY

GEAR

11/16 INCH

WASHER

FLAT

WASHER

MOUNTING

BRACKET

FIGURE 8-29. STARTER ASSEMBLY

SPRING

WASHER

MAGNETIC

HOUSING

ARMATURE

BRUSH

ENDCAP

THROUGH

BOLT

ES-1613-1s

8-30

Page 98

1. Carefully mount the starter on the endbell and tighten the mounting bolts to 30-33 lb-ft (41-45 Nm).

2. Install the engine bracket to the engine and install the muffler bracket hardware. Install the rear starter mounting nut.

3. Connect the positive (+) cable to the starter terminal.

4. Mount the housing on the genset and install the genset into the vehicle.

5. Reconnect the genset starting battery, negative (–) terminal last.

8-31

Page 99

8-32

Page 100

9. Generator

GENERATOR DESCRIPTION

The KY genset uses a 2-pole, revolving field, generator design. Output voltage is controlled by an electronic voltage regulator. A circuit breaker provides overcurrent protection for the generator and also functions as an on/off switch in the load circuit. AC load connections are made through generator lead wires that connect directly to a customer supplied junction box.

The generator section consists of the following components and controls:

• Stator and housing

• Rotor

• Brushes

• Electronic Voltage Regulator (VR1)

• Circuit Breaker (CB1)

• Wiring Harness

Stator and Housing

The stator consists of steel laminations stacked together, with three separate windings wound into slots in the laminations. Winding T1-T2 is the main power winding that provides the voltage and current to operate the connected loads. Winding B1-B2 is for battery charging and internal low voltage loads. Winding Q1-Q2 is an excitation winding that provides power to the voltage regulator for the rotor field winding. The stator assembly mounts inside the stator housing. Refer to Figure 9-1 on Page 9-3.

Generator Cooling

Cooling air for the generator is provided by a centrifugal fan mounted on the rotor shaft next to the bearing. A portion of the airflow from the fan is directed into the generator. Airflow through the generator cools the rotor and stator windings.

Brushes and Brush Block

The brush block is a one piece molded part that mounts on the endbell. There are two carbon brushes in the brush block that make contact with the slip rings on the rotor. The brushes provide the path for the controlled DC current from the regulator to the rotor field winding. Each brush is kept in contact with a slip ring by a spring located inside the brush block, behind the brush. The spring exerts the right amount of pressure to provide good contact and long brush life.

Electronic Voltage Regulator (VR1)

The electronic voltage regulator controls the output of the generator so the voltage remains constant under any load condition. The electronic voltage regulator takes power from the stator excitation winding, rectifies it, and feeds it into the field winding through the brushes and slip rings. The regulator continually measures the output of the power winding and regulates how much current should be fed into the field winding to maintain the proper output at various load levels.

Circuit Breaker (CB1)

Rotor

The rotor consists of steel laminations stacked together on a shaft. A field winding is wrapped around the laminations. The rotor shaft also has molded slip rings and a pressed on bearing. The entire assembly is connected directly to the tapered engine crankshaft by means of a through bolt. The rotor is supported by the engine bearing and by the endbell.

The rotor field winding provides the rotating magnetic field which in turn generates the voltage in the stator windings to power the connected loads. The magnetic field is established by a DC current flowing from the brushes through the slip rings and the field winding.

AC output from the generator is supplied to a circuit breaker located along side the control panel. The circuit breaker protects the generator windings from an overload or short circuit.

Wiring Harness

A wiring harness is provided for connecting the genset to the RV electrical system. All lead wires are stranded copper wire to withstand vibration. The lead wires must be protected with flexible conduit that must be provided by the RV manufacturer or genset installer. A 1/2-inch conduit elbow is provided to facilitate installation. The load wire conductor is black, the neutral conductor is white, and the ground conductor is green.

9-1