Part of the Kubota Repair Manuals.
This Kubota Workshop Manual covers the GH series gasoline engines: the GH120, GH130, GH170, GH170-1, GH250, GH280, GH340 and GH400. It runs to 104 pages under publication 97897-00915 and is written for teardown level service of these discontinued single cylinder engines.
The manual moves from specifications, performance curves and dimensions into the mechanism of the engine body, lubricating, fuel, ignition and starting systems, then into disassembly and servicing for each. You get engine identification, troubleshooting for starting difficulty, servicing specifications, carburetor and governor adjustment, ignition checks and full circuit diagrams.
With this PDF an owner or small engine mechanic can rebuild a GH engine, clean and set the carburetor, test the ignition, or chase a no start with exploded views and factory clearances instead of guesswork. Download it once and keep it on a phone, tablet or shop computer, and print the pages you need on the bench.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Specifications | Engine Specifications (Model, Type, Total Displacement, Bore X Stroke, Continuous Horsepower, Maximum Horsepower, Maximum Torque, No-Load Maximum Speed, No-Load Minimum Speed, Compression Ratio) | |
| Performance Curves | Gh120 (Brake Horsepower, Engine Speed, Fuel Consumption, Torque, Maximum Torque, Maximum Horsepower, Recommended Horsepower) | |
| Dimensions | Gh120, Gh130, Gh170, Gh170-1, Gh250 Gh280, Gh340, Gh400, Gh400-2 | |
| Feature | Cross Section (High Output and Low Fuel Consumption, Low Vibration and Low Noise), Contrast Between D.Q.P.S.G.I Types and R Type | |
| Engine Body (Mechanism) | Mechanical Decompression System (at Engine: Start, Running) | |
| Lubricating System (Mechanism) | Oil Pump, Relief Valve | |
| Fuel System (Mechanism) | Carburetor (Main Carburetor System, Slow System, Float), Governor | |
| Ignition System (Mechanism) | Transistor Magnet Ignition Type, Cdi Magnet Ignition Type | |
| Starting System (Mechanism) | Starter Operation Except for GH340, GH400 (When: Main Switch Is Turned to Start, Engine Starts, Starter Switch Is Released), Starter Components (Except for GH340, GH400) | |
| General | Engine Identification, Troubleshooting (Typical Troubles and Their Causes, In Cause of Difficulty with Engine Starting), Servicing Specifications (Engine Body) | |
| Engine Body (Disassembly and Servicing) | Checking and Adjusting, Disassembling and Servicing (External Components, Cylinder Head, Piston, Connecting Rod and Crankshaft, Except for GH400, GH400 Only) | |
| Lubricating System (GH400) | Checking, Disassembling and Assembling (Oil Pump, Relief Valve), Servicing (Oil Pump) | |
| Fuel System (Disassembly and Servicing) | Checking and Adjusting Carburetor (Engine Speed, Engine Idling Speed), Checking and Adjusting Governor (Governor and Maximum No-Load Speed) | |
| Ignition System (Disassembly and Servicing) | Checking Spark Plug (Spark Test), Checking Stop Switch (Switch Continuity), Checking Ignition Unit (Transistor Magnet Type, Cdi Magnet Type) | |
| Starting System (Disassembly and Servicing) | Starter, Disassembling and Assembling (Recoil Starter, Starter), Servicing | |
| Engine Circuit Diagram | GH120, GH170 Circuit Diagram (Wire Size and Color Indetification), GH130, GH170-1 GH250 GH280, GH340 GH400 Circuit Diagram (Wire Color), Component List |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Spark Plug Torque | 9.8 to 24.5 N-m | p. 47 |
| GH120, GH130 | ||
| Rotor Mounting Nut Torque (GH120, GH130) | 29.4 to 49.0 N-m | p. 47 |
| GH120, GH130, GH170, GH170-1 | ||
| Cylinder Head Screws Torque (M8 x 1.25) (GH120, GH130, GH170, GH170-1) | 24.5 to 35.3 N-m | p. 47 |
| Connecting Rod Screws Torque (M7 x 1.0) | 13.7 to 19.6 N-m | p. 47 |
| Rocker Arm Rock Nut Torque (M6 x 0.5) | 7.8 to 12.7 N-m | p. 47 |
| GH120, GH130, GH170-1 | ||
| Crankcase 2 Screws Torque (M6 x 1.0) | 9.8 to 14.7 N-m | p. 47 |
| GH170, GH170-1 | ||
| Rotor Mounting Nut Torque (GH170, GH170-1) | 58.8 to 73.6 N-m | p. 47 |
| GH170, GH250, GH280, GH340, GH400 | ||
| Crankcase 2 Screws Torque (M8 x 1.25) | 13.7 to 19.6 N-m | p. 47 |
| GH250, GH280 | ||
| Rotor Mounting Nut Torque (GH250, GH280) | 68.6 to 83.4 N-m | p. 47 |
| Cylinder Head Screws Torque (M8 x 1.25) (GH250, GH280) | 21.6 to 30.4 N-m | p. 47 |
| GH250, GH280, GH340, GH400 | ||
| Cylinder Head Screws Torque (M10 x 1.5) | 41.2 to 50.0 N-m | p. 47 |
| Connecting Rod Screws Torque (M8 x 1.25) | 23.5 to 29.4 N-m | p. 47 |
