Kohler CH18-CH25, CH620-CH730, CH740, CH750 Service Manual (24 690 06)

These Kohler CH18–CH25 and CH620–CH750 engines usually live on mowers, small loaders, and generators that work in dust, grass, and mud all day. This service manual is what I grab when I need to prove what’s actually wrong before I order parts. If an engine is hard to start hot, fouling plugs, or hunting at idle, I use this book to trace the problem step by step instead of guessing at coils or carburetors.

Applications & Use Cases

• Walk through systematic troubleshooting to isolate ignition, fuel, or governor faults before replacing components.
• Follow disassembly and reassembly sequences so you don’t miss seals, shims, or linkages during top‑end or governor work.
• Use adjustment procedures to set valves, governor linkage, and carb/choke so the engine pulls clean under load.
• Verify routing of fuel lines, breather hoses, and wiring after a partial teardown or repower.
• Cross-check parts visually while the engine is open to confirm you’re ordering the correct replacement pieces.

FAQ

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

A: Yes, it’s practical to keep it as a PDF, zoom in on diagrams, and avoid getting a paper copy oily.

Q: Is it worth printing sections?

A: I usually print only the procedures I’m doing that day, so I can mark notes and keep them right next to the engine.

Safety Note

Always lock out the equipment, let the engine cool, and disconnect the spark plugs before any inspection or adjustment.

Kohler CH18-CH25, CH620-CH730, CH740, CH750 Index:

2 Safety
3 Maintenance
5 Specifi cations
14 Tools and Aids
17 Troubleshooting
21 Air Cleaner/Intake
22 Fuel System
28 Governor System
30 Lubrication System
32 Electrical System
48 Starter System
57 Clutch
59 Disassembly/Inspection and Service
72 Reassembly

Kohler