Service manual for Kawasaki FH601D, FH641D, FH680D, FH721D 4‑stroke air‑cooled V‑twin gasoline engines, with specs, maintenance charts and troubleshooting.
This Service Manual is intended for trained mechanics and owners who need detailed maintenance, repair and troubleshooting information for Kawasaki FH601D, FH641D, FH680D and FH721D engines. It includes safety warnings, tool requirements, and step‑by‑step procedures for disassembly, inspection and re‑assembly.
The manual provides complete engine specifications, periodic maintenance intervals, torque values, special tools, emission control details and troubleshooting guides for both the engine and starter motor. Reference charts and diagrams help locate parts and service procedures quickly.
| Engine type | Forced air‑cooled, horizontal shaft, OHV, 4‑stroke gasoline |
|---|---|
| Bore x Stroke | 75.2 mm x 76 mm |
| Displacement | 675 mL |
| Low idle speed | 1550 rpm |
| Fast idle speed | 3600 rpm |
| Starting system | Electric starter |
| Oil capacity | 1.6 L |
The engine oil capacity is 1.6 L (1.7 US qt).
Low idle speed is 1550 rpm and fast idle speed is 3600 rpm.