P. O. Box 297 Whitewater, WI
Models 940-2
SERVICE MANUAL
SERIES IMPACT 36 PLUS
NOTICE TO USERS OF THIS MANUAL
SAFETY
REPLACEMENT PARTS
SPECIFICATIONS & CHARTS
SERVICE MANUAL
TABLE OF CONTENTS
TROUBLESHOOTING
Page
Series Impact 36 Plus
COMPONENTS TESTING
PART GENERAL INFORMATION
COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS
Page
ELECTROMAGNETIC INDUCTION
Section GENERATOR FUNDAMENTALS
MAGNETISM
ELECTROMAGNETIC FIELDS
Figure 5. Alternating Current Sine Wave
ALTERNATING CURRENT
ELECTRICAL UNITS
Figure 4. Operation of a Simple Generator
AMPERES = VOLTSOHMS
OHMS LAW
REACTANCE IN AC CIRCUITS
Figure 6. Electrical Units
CAPACITIVE REACTANCE
Figure 10. Block Diagram of the Impact 36 Plus System
Figure 9. Capacitive Reactance
Section GENERATOR FUNDAMENTALS
Section GENERATOR FUNDAMENTALS
WHY VARIABLE SPEED CONTROL?
Page
Section GENERATOR FUNDAMENTALS
INTRODUCTION
UPPER FAN HOUSING
Figure 2 Permanent Magnet Rotor Assembly
Section MAJOR GENERATOR COMPONENTS
STEPPER MOTOR
STATOR ASSEMBLY
ROTOR HUB
STATOR RETAINING RING
Page
Figure 5. Schematic- Stator Windings
Section MAJOR GENERATOR COMPONENTS
Page
Section MAJOR GENERATOR COMPONENTS
OPERATIONAL DESCRIPTION
Figure 1. Block Diagram- A Generator System
Section OPERATIONAL ANALYSIS
GENERAL
Section OPERATIONAL ANALYSIS
OPERATIONAL DESCRIPTION CONTINUED
INSULATION RESISTANCE TESTERS
CAUTION! When using a Megohmmeter or
Section INSULATION RESISTANCE
DIRT AND MOISTURE
RESULTS OF TESTS
CLEANING THE GENERATOR
TEST ALL STATOR WINDINGS TO GROUND
TEST FOR SHORTS BETWEEN WINDINGS
CAUTION! Some generators use epoxy or
Figure 3. Schematic - Stator Windings
DRYING THE GENERATOR
DANGER! DO NOT WORK WITH SOLVENTS
Page
Section INSULATION RESISTANCE
INTRODUCTION
Section COMPONENTS TESTING
Figure 1. Stator Leads
STATOR ASSEMBLY
Section COMPONENTS TESTING
STATOR ASSEMBLY CONTINUED
Figure 2. Schematic- Stator Windings
Section COMPONENTS TESTING
TESTING THE BATTERY CHARGE CIRCUIT
Figure 3. Battery Charge Windings and Rectifier
Figure 4. Battery Charge Circuit
Page
Section COMPONENTS TESTING
Figure 1. Exploded View of Control Panel
Section CONTROL PANEL
CONSTRUCTION
COMPONENTS
Page
Section CONTROL PANEL
GENERAL
Section SHEET METAL
Impact Plus Generator
TO CARBURETOR
EXPLODED VIEW OF SHEET METAL GASOLINE UNITS
Section SHEET METAL
Page
DESCRIPTION
PARTS LIST FOR SHEET METAL GASOLINE UNITS
Section SHEET METAL
DESCRIPTION
Page
EXPLODED VIEW OF SHEET METAL LP UNITS
Section SHEET METAL
DESCRIPTION
PARTS LIST FOR SHEET METAL GASOLINE UNITS
Section SHEET METAL
DESCRIPTION
Page
Section SHEET METAL
COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS
2.3 PISTON, RINGS, CONNECTING ROD 2.4 CRANKSHAFT & CAMSHAFT
PART ENGINE MECHANICAL
2.1 GENERAL INFORMATION 2.2 VALVE TRAIN
Page
Figure 1. Intake Stroke Figure 2. Compression Stroke
Figure 3. Power Stroke Figure 4. Exhaust Stroke
Section GENERAL INFORMATION
4-CYCLE ENGINE THEORY
NOTE DO NOT MIX OIL WITH THE GASOLINE
RECOMMENDED FUELS
RECOMMENDED ENGINE OIL
NOTE DO NOT USE GASOLINE CONTAINING METHANOL
Section GENERAL INFORMATION
THE UNIT IS NOW READY FOR SERVICE
STORAGE INSTRUCTIONS
ENGINE TUNE-UP
DESCRIPTION
NOTE 1- Item 36 Includes valve seats and guides
Section GENERAL INFORMATION
EXPLODED VIEW OF ENGINE LONG BLOCK
Figure 1. Valve Train Components
Section VALVE TRAIN
VALVE TRAIN COMPONENTS
VALVE COMPONENTS REMOVAL
Figure 5. Removal of Valve Spring
VALVE SERVICE
DANGER! ALWAYS WEAR SAFETY GLASSES WHEN REMOVING THE VALVE SPRINGS
Figure 4. Cylinder Head Removal
Figure 10. Valve Tappet
VALVE COMPONENTS INSTALLATION
Figure 11. Installation of Intake and Exhaust Valves
Figure 8. Valve Guides
Figure 14. Install Rocker Arm & Pivot Ball stud
VALVE COMPONENTS INSTALLATION CONTINUED
ADJUSTING VALVE CLEARANCE
Figure 12. Installing Valve Spring Washers
Figure 17. Tightening Pivot Ball Jam Nut
ROCKER ARM COVER INSTALLATION
Figure 16. Adjusting Valve Clearance
Figure 18. Rocker Arm Cover Installation
Page
Section VALVE TRAIN
PRIOR TO REMOVAL
Section PISTON, RINGS, CONNECTING ROD
Figure 1. Piston, Rings and Connecting Rod
OVERSIZE PISTON & RINGS
Figure 6. Ring to Groove Side Clearance
PISTON RINGS
Figure 4. Piston Minor Diameter
Figure 5. Piston Major Diameter
Figure 7. Ring Locations in Piston Grooves
CONNECTING ROD
ASSEMBLY AND INSTALLATION
Figure 9. Connecting Rod
Section PISTON, RINGS, CONNECTING ROD
CYLINDER SERVICE
Figure 10. Match Marks on Rod and Cap
CRANKSHAFT REMOVAL
Section CRANKSHAFT AND CAMSHAFT
CRANKCASE COVER REMOVAL
CAMSHAFT REMOVAL
Figure 5. Points to Check on Crankshaft
CAMSHAFT INSPECTION
CRANKSHAFT INSPECTION
Figure 4. Points to Check on Camshaft
Figure 6. Bearing Bore in Crankcase Cover
INSTALLING THE CRANKSHAFT
INSTALLING THE CAMSHAFT
COMPRESSION RELEASE MECHANISM
Page
Figure 9. Timing Mark on Crankshaft Gear
Figure 10. Alignment of Timing Marks
Section CRANKSHAFT AND CAMSHAFT
FILTER & FUEL PUMP
AIR CLEANER & AIR INTAKE
PART GASOLINE FUEL SYSTEM
INTRODUCTION TO FUEL SYSTEM
Page
DANGER! ATTEMPTING TO WELD OR BRAZE
Section INTRODUCTION TO FUEL SYSTEM
RECOMMENDED FUEL
EVAPORATION CONTROL SYSTEMS
Page
Figure 2. Typical Gasoline Fuel System
Section INTRODUCTION TO FUEL SYSTEM
AIR INTAKE
Section AIR CLEANER AND INTAKE
AIR CLEANER
Figure 1. Engine Air Cleaner
Page
Section AIR CLEANER AND INTAKE
Figure 1. Fuel Filter Typical
Section FUEL FILTER AND FUEL PUMP
FUEL FILTER
FUEL PUMP
Page
Section FUEL FILTER AND FUEL PUMP
CARBURETOR OPERATION
Section CARBURETOR
GENERAL INFORMATION
DESCRIPTION
Section CARBURETOR
CARBURETOR DISASSEMBLY
CLEANING AND INSPECTION
Figure 3. Carburetor Exploded View
ENGINE SPEED
ADJUSTMENT
THROTTLE LINKAGE ADJUSTMENT
Figure 5. Adjusting Throttle Linkage
Page
Figure 6. Carburetor Removal
Section CARBURETOR
OPERATION
OPERATIONAL CHECK AND ADJUSTMENT
Figure 2. Choke Adjustment
Section AUTOMATIC CHOKE
Page
Section AUTOMATIC CHOKE
Figure 1. Speed Control System
STEPPER MOTOR PROBLEMS
Section SPEED CONTROL SYSTEM
A6060 CIRCUIT BOARD
Section SPEED CONTROL SYSTEM
TESTING THE STEPPER MOTOR
Figure 2. The Stepper Motor Connector Figure 3. The Stepper Motor
4.3 CARBURETOR
Air Cleaner & Air Intake Section Speed Control System Section
PART GASEOUS FUEL SYSTEM
4.1 INTRODUCTION TO FUEL SYSTEM 4.2 SHUTOFF VALVE & REGULATOR
Page
IMPORTANT CONSIDERATIONS
ADVANTAGES OF GASEOUS FUELS
FUEL SYSTEM COMPONENTS
VAPOR WITHDRAWAL
Figure 1. A Typical LP Gas Fuel System
FUEL SUPPLY LINES
EXCESS FLOW VALVE
IMPORTANT CONSIDERATIONS CONTINUED
DANGER! DO NOT USE FLAME TO CHECK
LEAKAGE TESTING
Figure 2. Gas Carburetion Diagram
GASEOUS CARBURETION
Page
Section INTRODUCTION TO FUEL SYSTEM
Section SHUTOFF VALVE AND REGULATOR
ADJUSTMENTS
TESTING THE FUEL LOCKOFF SOLENOID
DANGER! DO NOT ATTEMPT TO ADJUST
RESULTS OF TEST
If battery voltage is Indicated but the solenoid does NOT ener
If battery voltage is NOT Indicated, a problem exists In the DC
Section SHUTOFF VALVE AND REGULATOR
Figure 1. LP Gas Carburetor
CARBURETOR ADJUSTMENT
DISASSEMBLY AND REASSEMBLY
CARBURETION
Page
Section CARBURETOR
Series Impact 36 Plus
PART ENGINE OIL COOLING SYSTEM
5.1 ENGINE OIL SYSTEM 5.2 ENGINE COOLING SYSTEM
COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS
Page
OIL PUMP
Figure 1. Oil System Diagram
Section ENGINE OIL SYSTEM
INTRODUCTION TO OIL SYSTEM
PRESSURE RELIEF VALVE
BREATHER ASSEMBLY
OIL PUMP CONTINUED
CRANKSHAFT OIL SEALS
Figure 7. Oil Filter Support
Figure 6. Breather Assembly
OIL SUMP
OIL FILTER SUPPORT
Page
Section ENGINE OIL SYSTEM
Figure 1 - Air Flow Through Engine-Generator
Section ENGINE COOLING SYSTEM
GENERATOR AIR FLOW
COOLING AIR INLET OPENINGS
INVERTER LOCATION
TESTING THE INSTALLATION
CAUTION Do not install the inverter in the
COMPENSATING FOR RESTRICTIONS
A6060 CIRCUIT BOARD
ENGINE SHUTDOWN FEATURES
PART ENGINE ELECTRICAL SYSTEM
ENGINE DC CONTROL SYSTEM
Page
GENERAL
Figure 1. Schematic- Engine DC Control System
Section ENGINE DC CONTROL SYSTEM
BOARD
HOW IT WORKS
NOTE Also see Section 3.5, AUTOMATIC
CHOKE and Section 6.2, A6060 CIRCUIT
Section 6.2 A6060 CIRCUIT BOARD
WIRE
battery is connected
NOTE 1 - See SHUTDOWN FEATURES” In Section 6.5 Page
CIRCUIT BOARD CONNECTIONS CONTINUED
Section A6060 CIRCUIT BOARD
CABLE LENGTH
BATTERY
Figure 1. Schematic - Cranking Circuit
Section ENGINE CRANKING SYSTEM
Section ENGINE CRANKING SYSTEM
BATTERY CONTINUED
START-RUN-STOP SWITCH SW1
STARTER CONTACTOR
Section ENGINE CRANKING SYSTEM
STARTER MOTOR
Figure 3. Starter Contactor
Figure 4. Starter Motor
Page
Section ENGINE CRANKING SYSTEM
Section ENGINE IGNITION SYSTEM
IGNITION CAGE ASSEMBLY
Figure 1. Ignition Cage Assembly
Figure 3. Ignition Sensor Schematic
IGNITION MODULE CONTINUED
TESTING THE SYSTEM
Figure 7. Ignition System Diagram
Figure 6. Setting Spark Plug Gap
Figure 9. Checking Engine Miss
Figure 8. Testing for Spark
Warning! Do NOT use a screwdriver to test for
spark. Personal injury or damage to equip- ment may result
Note Only one spark should be observed upon initial cranking
TESTING THE SYSTEM CONTINUED
Figure 12. Testing Ignition Sensor
Figure 13. Testing Ignition Coil Figure 14. Testing Ignition Module
Figure 3. Testing the Oil Temperature Switch
Section SHUTDOWN FEATURES
OIL PRESSURE SWITCH
OIL TEMPERATURE SWITCH
Section SHUTDOWN FEATURES
ADDITIONAL SHUTDOWN FEATURES
GENERAL
Section OPTIONAL REMOTE PANEL
Figure 1. Remote Panel Plug-In Receptacle
Figure 2. Optional Remote Panel Models 004057 and
Page
Section OPTIONAL REMOTE PANEL
COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS
PART TROUBLE SHOOTING
7.2 ENGINE DC CONTROL SYSTEM/ AC TROUBLESHOOTING
7.1 GENERATOR & SPEED CONTROL
Page
Page
TROUBLESHOOTING REFERENCE CHART
Section GENERATOR & SPEED CONTROL SYSTEM
Page
Section GENERATOR & SPEED CONTROL SYSTEM
INTRODUCTION
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
PROBLEM 1- PRIMING FUNCTION DOES NOT WORK
Page
PROBLEM 2 - ENGINE WILL NOT CRANK
PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START CONTINUED
Page
PROBLEM 4 - ENGINE STARTS HARD AND RUNS ROUGH
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
Page
PROBLEM 5 - ENGINE STARTS THEN SHUTS DOWN AFTER A FEW SECONDS
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
SHUTS DOWN TEST TEST INVERTER Pg FAIL REPLACE INVERTER
Page
PROBLEM 6 - GENERATOR DOESN’T PULL FULL LOAD
PROBLEM 7 - GENERATOR CIRCUIT BREAKER TRIPS / NO AC VOLTAGE
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
Page
PROBLEM 8 - ENGINE SHUTS DOWN UNDER LOAD
PROBLEM 9 - GENERATOR LOSES AC POWER THEN SHUTS DOWN
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
Page
PROBLEM 10 - NO AC OUTPUT
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
12-WIRE
Page
PROBLEM 10 - NO AC OUTPUT CONTINUED
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
TEST 1- CHECK 7.5 AMP FUSE
TEST 3- CHECK POWER TO FUEL PUMP
TEST 2- CHECK POWER TO PRIMER SWITCH
Figure 2. Primer Switch
TEST 4- CHECK BATTERY/BATTERY CIRCUIT
TEST 6- TEST PRIMER SWITCH
TEST 7- CHECK WIRE 14A TO FUEL PUMP
TEST 8- CHECK POWER SUPPLY TO STARTER MOTOR
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
TEST 9- CHECK WIRE 56 POWER TO STARTER CONTACTOR
TEST 10- CHECK A6060 CIRCUIT BOARD POWER SUPPLY
Figure 5. Starter Contactor
TEST 13- CHECK FUEL SUPPLY
TEST 12- TEST START-STOP SWITCH
Figure 7. Start-Stop Switch
TEST 11- TEST STARTER CONTACTOR
TEST 18- CHECK IGNITION SENSOR
TEST 21 - CHECK A6060 CIRCUIT BOARD OUTPUT TO WIRE
TEST 17- CHECK IGNITION POWER SUPPLY
Figure 9. Ignition Module & 4-Tab Connector
Figure 10. Receptacle J2
TEST 23- CHECK CARBURETION
TEST 22-TEST AUTOMATIC CHOKE
TEST 24- CHECK ENGINE
TEST 28 - DC LINK VOLTAGE TEST
TEST 27- TEST OIL TEMPERATURE SWITCH
TEST 26- TEST OIL PRESSURE SWITCH
Note Cap the DC Link wires with a wire nut for safety
Figure 10 Free End of 12 Position Harness
TEST 30 - 12 POSITION HARNESS SIGNALS TEST
TEST 29 - 12 POSITION HARNESS CONTINUITY TEST
Note Fluke 87 true RMS meter used in test
TEST 31 - STATIC TESTS ON INVERTER
STATOR TESTS TEST 32 - POWER SUPPLY WINDING TEST
Figure 11. 12 Position Connector on Inverter
Pin 4 Wire #14
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
TEST 36 - AC POWER WINDING TEST AC1/AC2/SL1/SL2
TEST 34 -STATOR RESISTANCE VALUES
TEST 35 - BRIDGE RECTIFIER TEST
Page
Section ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
Wiring Diagram
PART SPECIFICATIONS AND CHARTS
General Specifications
Electrical Schematic
Page
LOAD %
ENGINE SPEEDS AND VOLTAGE SPECIFICATIONS
Part
NOMINAL RESISTANCES OF GENERATOR WINDINGS
Page
Part SPECIFICATIONS & CHARTS
ELECTRICAL SCHEMATIC DRAWING NO. 0D4947-B
1 OF
Page
WIRING DIAGRAM DRAWING NO. 0D4947-B
Part SPECIFICATIONS & CHARTS
2 OF
Part SPECIFICATIONS & CHARTS
GENERAL SPECIFICATIONS
MODEL
GV-220
Later model small frame GN engines have no crankshaft sleeve bearing
SPECIFICATIONS & CHARTS
CRANKCASE ASSEMBLY
CRANKCASE COVER ASSEMBLY
Part SPECIFICATIONS & CHARTS
CONNECTING ROD ASSEMBLY
CRANKSHAFT
PISTON
MODEL
PISTON CONTINUED
Part SPECIFICATIONS & CHARTS
Part SPECIFICATIONS & CHARTS
CAMSHAFT ASSEMBLY
OIL PUMP
NOTE 2 Measure pump tip clearance on shaft in crankcase cover
MODEL
SPECIFICATIONS & CHARTS
Part
MODEL
Page
MAJOR FEATURES AND DIMENSIONS GENERATOR
Part SPECIFICATIONS & CHARTS
Page
MAJOR FEATURES AND DIMENSIONS INVERTER
Part SPECIFICATIONS & CHARTS
