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