This service manual has been written and published by the Product Manufacturer to aid dealers’
mechanics and company service personnel when servicing the products described herein.
Specifications...........................................................2
Part 1 – General Information...................................9
Section 1.1 – Generator Fundamentals.................10
Magnetism........................................................10
Electromagnetic Fields.....................................10
Electromagnetic Induction................................10
A Simple AC Generator....................................11
A More Sophisticated AC Generator.................11
Section 1.2 – Measuring Electricity........................13
Meters..............................................................13
The VOM...........................................................13
Measuring AC Voltage......................................13
Measuring DC Voltage......................................13
Measuring AC Frequency.................................13
Measuring Current............................................14
Measuring Resistance......................................14
Electrical Units..................................................15
Ohm's Law........................................................15
Section 1.3 – Brushless, CapacitorExcitation System.............................16
Introduction.......................................................16
Stator Assembly................................................16
Rotor Assembly.................................................16
Circuit Breakers................................................16
Operation..........................................................17
Section 1.4 – Brushed Excitation System..............18
Introduction.......................................................18
Stator Assembly................................................18
Brush Holder and Brushes................................18
Rotor Residual Magnetism...............................18
Voltage Regulator.............................................18
Operation..........................................................18
Section 1.5 – Testing, Cleaning and Drying...........20
Insulation Resistance........................................20
The Megohmmeter...........................................20
Stator Insulation Resistance Test......................20
Cleaning the Generator.....................................21
Drying the Generator........................................21
Part 2 – AC Generators..........................................21
Section 2.1 – Brushless CapacitorTroubleshooting Flowcharts..............22
Section 2.2 – Brushed ExcitationTroubleshooting Flowcharts..............24
Section 2.3 – AC Diagnostic Tests.........................26
Introduction.......................................................26
Test 1 – Check No-Load Voltageand Frequency.....................................26
Test 2 – Check Circuit Breaker.........................26
Test 3 – Check Continuity ofReceptacle Panel.................................26
Test 4 – Field Flash Alternator(Configuration "A" Only)........................27
Test 5 – Check Brushed Rotor Circuit...............28
Test 6 – Check Capacitor..................................29
Test 7 – Test Brushless DPE Winding...............30
Test 8 – Test Brushless Stator Windings...........30
Test 9 – Test Brushed Stator Windings.............31
Test 10 – Check Load Voltage & Frequency.....31
Test 11 – Check Load Watts & Amperage........31
Test 12 – Adjust Voltage Regulator...................31
Part 3 – Engine Troubleshooting...........................33
Section 3.1 – 389/206/163cc Troubleshooting Flowcharts........................................34
Section 3.2 – 410cc Troubleshooting Flowcharts...37
Section 3.3 – Diagnostic Tests...............................42
Test 20 – Check 1.5 Amp Fuse.........................42
Test 21 – Check Battery & Cables....................42
Test 22 – Check Voltage atStarter Contactor (SC).........................42
Test 23 – Check Start-Run-Stop Switch...........42
Test 24 – Test OFF-ON Switch..........................43
Test 25 – Check Starter Motor..........................43
Test 25 – Check Ignition Spark.........................45
Test 26 – Check Spark Plugs............................46
Test 29 – Check Carburetion............................46
Test 30 – Choke Test.........................................47
Test 33 – Check Valve Adjustment....................47
Test 36 – Check Engine / Cylinder Leak Down Test / Compression Test.......................48
Test 38 – Check Flywheel.................................48
Test 39 – Remove Wire 18 / Shutdown Lead....49
Test 40 – Check / Adjust Governor (389cc Engine).....................................49
Test 41 – Check / Adjust Governor (410cc Engine).....................................50
Test 45 – Check Oil Level Switch......................51
Test 46 – Check Oil Pressure Switch................51
Test 49 – Test Recoil Function..........................52
Test 50 – Test Engine Function.........................52
Part 4 – Disassembly..............................................53
Section 4.1 – Major Disassembly...........................54
Part 5 – Electrical Data...........................................71
Electrical Schematic, GP1850...............................72
Electrical Schematic, GP3250...............................73
Electrical Schematic, GP5000/5500/GP6500........74
Wiring Diagram, GP5000/5500/GP6500................75
Electrical Schematic, GP7000E/GP8000E............76
Wiring Diagram, GP7000E/GP8000E....................77
Electrical Formulas................................................78