Generac Power Systems XT-EFI Series

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Section 1 EFI Engine Control Diagnostic Tests

20 Diagnostic Repair Manual

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Read this Manual Thoroughly2
Replacement Parts2
Rotor and Stator Resistance Tables3
Table of Contents5
Section 1 Brushless Capacitor Excitation7
Introduction7
Stator Assembly7
Rotor Assembly7
Operation8
Troubleshooting Flowcharts9
If Problem Involves AC Output9
Problem 1 - Generator Produces Zero Voltage or Residual Voltage9
Problem 2 - Voltage & Frequency Are both High or Low10
Problem 3 - Excessive Voltage/Frequency Droop When Load Is Applied10
Problem 4 - Generator Produces High Voltage at No-Load10
Section 2 Direct Excitation (Brush Type)11
Introduction11
Stator Assembly11
Brush Holder and Brushes11
Voltage Regulator11
Operation11
Troubleshooting Flowcharts13
If Problem Involves AC Output (Brush Type)13
Problem 5 - Generator Produces Zero Voltage or Residual Voltage13
Problem 6 - Voltage & Frequency Are both High or Low14
Problem 7 - Excessive Voltage/Frequency Droop When Load Is Applied14
Problem 8 - Generator Produces High Voltage at No-Load14
Section 3 AC Diagnostic Tests15
Test 1 - Check No-Load Voltage and Frequency15
Test 2 - Check Main Circuit Breaker15
Test 3 - Check Continuity of Receptacle Panel15
Test 4 - Fixed Excitation Test/Rotor Amp Draw Test16
Test 5 - Field Flash Alternator18
Test 6 - Check Capacitor19
Test 7 - Test Brushless DPE Windings19
Test 8 - Test Brushless Stator Windings20
Test 9 - Test Brushed Stator Windings20
Test 10 - Check Load Voltage & Frequency20
Test 11 - Check Load Watts & Amperage20
Test 12 - Adjust Voltage Regulator21
Test 13 - Voltage Changeover Switch 120/240 Position21
Section 4 EFI Engine Control Diagnostic Tests23
Basic EFI Theory23
Basic Open-Loop Theory23
Engine Requirements23
Fuel System23
Air Metering and Measurement24
Sensor Inputs24
Basic Operation24
EFI Fault Code Diagnostics25
Section 5 Engine Diagnostic Tests27
Diagnostic Flow Charts27
Problem 9 - Recoil Cord will Not Pull (208/389/420/459Cc Engines)27
Problem 10 - Engine Starts Hard and Runs Rough (208/389/420Cc Non-EFI Engines)27
Problem 11 - Engine Turns over but will Not Start (208/389/420Cc Non-EFI Engines)28
Problem 12 - Engine "Hunts" / Erratic Idle (208/389/420Cc Non-EFI Engines)28
Problem 13 - Engine will Not Crank (220/410/530Cc Engines with Electric Start)29
Problem 14 - Recoil Cord will Not Pull (if so Equipped) (220/410/459/530Cc Engines)29
Problem 15 - Engine Cranks but will Not Start (220/410/530Cc Non-EFI Engines)30
Problem 16 - Engine Starts Hard and Runs Rough (220/410/530Cc Non-EFI Engines)31
Problem 17 - Engine Starts then Shuts down (220/410/530Cc Non-EFI Engines)31
Problem 18 - Battery will Not Charge (220/410/459/530Cc Engines)31
Problem 19 - Engine "Hunts" / Erratic Idle (220/410/530Cc Non-EFI Engines)32
Problem 20 - Unit will Not Idle (220/410/426/530Cc Non-EFI Engines)32
Problem 21 - Unit will Not Come off Idle (220/410/426/530Cc Non-EFI Engines)32
Introduction33
Test 14 - Check Fuse33
Test 15 - Check Battery and Cables33
Test 17 - Check START-RUN-STOP Switch (410/426Cc Engine)34
Test 18 - Test OFF-ON Switch34
Test 19 - Check Starter Motor34
Test 20 - Check Ignition Spark35
Test 21 - Check Spark Plugs36
Test 22 - Check Carburetion36
Test 23 - Choke Test37
Test 24 - Check Valve Adjustment37
Test 25 - Check Engine / Cylinder Leak down Test / Compression Test38
Test 26 - Check Ignition Coil39
Test 27 - Check Flywheel39
Test 28 - Remove Shutdown Wire40
Test 29 - Check / Adjust Governor (208/389/420Cc Non-EFI Engine)40
Test 30 - Check / Adjust Governor (220/410/530Cc Non-EFI Engine)41
Test 31 - Check Oil Pressure Switch41
Test 32 - Check Oil Level Switch42
Test 33 - Test Recoil Function42
Test 34 - Test Engine Function42
Test 35 - Test Battery Charger (Non-EFI Units)42
Test 36 - Test Battery Charging Circuit (EFI Electric Start Models)43
Test 37 - Test Idle Control43
Section 6 Major Disassembly45
Introduction45
Section 7 Electrical Data55
Introduction55
Wiring Diagram and Electrical Schematic, RS5500 Drawing No. 0K6393-A56
Wiring Diagram and Electrical Schematic, RS7000E Drawing No. 0K6394-C60
Wiring Diagram and Electrical Schematic, XC6500 Drawing No. 10000010344-A64
Wiring Diagram and Electrical Schematic, XC6500E/XC8000E Drawing No. 10000010343-A68
Wiring Diagram and Electrical Schematic, XP4000 Drawing No. 0H8536-D72
Wiring Diagram and Electrical Schematic, XP5600E & XP6400E Drawing No. 0K2042-A76
Wiring Diagram and Electrical Schematic, XP6500E Drawing No. 0H6809-D78
Wiring Diagram and Electrical Schematic, XP6500E Drawing No. 0H6809-D81
Wiring Diagram and Electrical Schematic, XP8000E Drawing No. 0H7588-C82
Wiring Diagram and Electrical Schematic, XP10000E Drawing No. 0H7214-D86
Wiring Diagram and Electrical Schematic, XG4000 Drawing No. 0H3339-E90
Wiring Diagram and Electrical Schematic, XG4000 Drawing No. 0H5278-A92
Wiring Diagram and Electrical Schematic, XG5600E/XG6400E Drawing No. 0J8223-B94
Wiring Diagram and Electrical Schematic, XG6500 Drawing No. 0H2780-F96
Wiring Diagram and Electrical Schematic, XG7000E Drawing No. 0H3525-C98
Wiring Diagram and Electrical Schematic, XG8000E Drawing No. 0H5145-A100
Wiring Diagram and Electrical Schematic, XG10000E Drawing No. 0H3931-B102
Wiring Diagram and Electrical Schematic, XT8000E Drawing No. 0K2800-C106
Wiring Diagram and Electrical Schematic, HL6500E Drawing No. 0L2474-A107
Wiring Diagram and Electrical Schematic, HL6500E Drawing No. 0K9434-B109
Wiring Diagram and Electrical Schematic, HL6500E Drawing No. 0K9433-B110
Wiring Diagram, XT8000EFI Drawing no112
10000023894-A112
Electrical Formulas113

Generac Power Systems XT-EFI Series

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