Kohler LH630, LH640, LH685, LH690, LH750, LH755 Service Manual (66_690_01)

These Kohler LH630–LH755 engines usually live on mowers, small construction gear, and other outdoor power equipment that run hard in dusty, hot conditions. This service manual is what I’d pull out when an engine won’t start cleanly, surges under load, or is down on power and I need to prove the cause before ordering parts. For example, if one of these engines is hard to restart when hot, I’d follow the manual’s diagnostic flow to separate a fuel issue from ignition or compression, then use the step‑by‑step teardown guidance to inspect only what’s necessary.

Applications & Use Cases

• Trace no-start or hard-start complaints by systematically checking ignition, fuel, and basic mechanical condition.
• Isolate surging, hunting, or poor idle to carburetion, governor setup, or intake leaks before replacing components.
• Follow the correct disassembly/assembly sequence on shrouds, carb, and cylinder heads so nothing gets forced or misaligned.
• Verify and adjust governor linkages and throttle controls after repairs so the engine holds speed under load.
• Inspect and reseal gaskets and mating surfaces after overheating or oil leaks to prevent repeat failures.

FAQ

Q: Can I use this manual on a tablet in the field?

A: Yes, it works well digitally; you can zoom diagrams and use search to jump to the system you’re working on.

Q: Should I print the whole thing or just parts of it?

A: Most techs print only the procedures and diagrams for the job at hand and keep the full manual stored electronically.

Safety Note

Always disable the ignition and secure the equipment before opening covers, removing guards, or working near rotating parts.

Kohler LH630, LH640, LH685, LH690, LH750, LH755 Index:

• Safety
• Maintenance
• Specifications
• Tools and Aids
• Troubleshooting
• Air Cleaner/Intake
• Fuel System
• Governor System
• Lubrication System
• Electrical System
• Starter System
• Cooling System
• Disassembly/Inspection and Service
• Reassembly

Kohler