Part of the Kubota Repair Manuals.
This is the official Kubota workshop manual for the AV1600, AV2500, AV3800, AV4500, AV5500, and AV6500 generators, a 70-page PDF. These units run the GH120, GH170, GH250, GH280, and GH400 engines, and the manual covers both the generator end and the engine.
It opens with specifications, dimensions, and full wiring diagrams, then explains the mechanism, including the oil watching system, auto idler system, and auto choke. From there it moves into disassembling and servicing, with troubleshooting, tightening torques, a maintenance check list, and detailed generator and engine service procedures.
Use it to chase a no-output or unstable-voltage fault, test the field and DC output, set spark plug gap and torque, adjust valve clearance, and rebuild the engine to the factory allowable limits after years of storage or hard use.
What's Inside This Kubota AV1600–AV6500 Series Manual
| System | Pages | Key Topics |
|---|---|---|
| Specifications | 9-12 | Generator, Engine, Standard Voltage, Ampere Frequency, Receptacle |
| Dimensions | 13 | Model, A, B, C |
| Wiring Diagram | 14-22 | Generator, Control Box, Engine, Ignition Control Unit, Receptacle, Color of Wiring |
| Mechanism | 23-28 | Feature (Engine Body, Oil Watching System, Auto Idler System, Auto Choke) |
| Disassembling and Servicing | 29-43 | General (Generator Identification, Lubricants and Fuel, Troubleshooting, Tightening Torques, Maintenance Check List, Check and Maintenance, Special Tools), External Component |
| External Components | 44 | Fuel Tank, Muffler Cover, Muffler, Control Box, Air Cleaner Assy. |
| Generator | 45-50 | Receptacles, Diode Stack, Capacitor, A.v.r., Stator, Rotor, Brush Holder |
| Engine | 51-70 | Checking and Adjusting |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| AV1600, AV2500 | ||
| Cylinder Head Screws Torque (GH120, GH170) | 24.5 to 32.4 N·m | p. 37 |
| All Models | ||
| Air cleaner element replacement interval | Every year or every 6 times of cleaning | p. 38 |
| Fuel filter cleaning interval | Every 200 hours | p. 38 |
| Spark Plug Tightening Torque | 9.8 to 24.5 N·m | p. 37 |
| DC Output Voltage | 8 to 18 V | p. 45 |
| AV5500, AV6500 | ||
| Oil strainer cleaning interval (GH400 only) | Every 200 hours | p. 38 |
| Commutator O.D. (Allowable Limit) | 27.0 mm | p. 69 |
| Brush Length (Allowable Limit) | 6.0 mm | p. 69 |
| Engine Oil Capacity (AV5500, AV6500) | 1.1 l | p. 10 |
| AV1600, AV2500, AV3800, AV4500 | ||
| Spark plug gap (GH120, GH170, GH250, GH280) | 0.6 to 0.7 mm | p. 40 |
| AV3800, AV4500, AV5500, AV6500 | ||
| Field Voltage (Checking under the no load) | 15 to 40 (V) D.C. | p. 46 |
| AV1600 | ||
| Engine Oil Capacity, AV1600 | 0.55 l | p. 9 |
