Description

Kohler CH18-CH26, CH620-CH750 Service Manual

You need torque values? Page 26 has the head bolt pattern for the CH25. You need to know why an engine won’t pull fuel? Section 5 covers the Fuel System and Governor – including the LPG and EFI sub-sections. I’ve been turning wrenches for 28 years, and I’ll tell you straight: if you’re working on a Kohler Command horizontal crankshaft without this factory manual, you’re wasting time and risking a come-back. This isn’t some repackaged aftermarket manual full of rounded-off numbers. It’s 246 pages of what Kawasaki’s technicians use in the field.

Why OEM Documentation Matters on This Job

Aftermarket manuals save a few bucks but cost you hours. They’ll tell you “tighten the head bolts” without giving the sequence or the angle. This manual gives you the factory angles. Section 11 – Reassembly – has the exact torque sequence for every cylinder head on these engines. I’ve seen a CH620 ruined because someone used a generic torque chart from the internet. Don’t be that guy. Stick with the factory print.

Fuel System Diagnosis: Where Most Guys Get Stuck

Section 5 covers the Fuel System and Governor. Section 5A dives into LPG Fuel Systems – float settings, pressure checks. Section 5B covers Electronic Fuel Injection (EFI) Fuel System – injector resistance values, throttle position sensor testing. If your engine cranks but won’t fire, you need the fuel pressure spec from page 73. That page also lists the return line restriction test. I’ve fixed three CH740s this month using that data. If you’re converting a generator to LPG, you’ll need the data from Section 5A – it’s in this book.

Electrical System and Components – Read This Before You Test

Section 8 covers the Electrical System and Components. Charging coil resistance values, rectifier-regulator tests, ignition timing specs. The starter motor disassembly is in Section 7 (Retractable Starter) but the wiring harness pinouts are in Section 8. I watch guys burn out an ECU by back-probing the wrong terminal. The manual gives you the correct test points. Use a DMM and follow the procedure on page 112. That page saved me a $400 controller replacement last week.

Disassembly, Inspection, Reassembly – The Core of the Manual

Sections 9 through 11 are where the real work happens. Section 9 – Disassembly – has the crankcase bolt torque values and the flywheel puller instructions. Section 10 – Inspection and Reconditioning – tells you what to look for on cam lobes, cylinder walls, and valve guides. Section 11 – Reassembly – includes the ring gap checks and the lubrication sequence for the governor gear. If you skip the step where you oil the governor shaft (page 188), you’ll get a loose bushing in 50 hours. I’ve seen it. The manual doesn’t let you skip.

Does This Manual Cover the Kohler CH25 Horizontal Crankshaft?

Yes, the CH18-CH26 range includes the CH25. Also CH620-CH750 includes the CH740, CH730, CH750. The manual covers all horizontal crankshaft Command models within those ranges. If you need the vertical shaft version, see the related manuals below.

Related manuals you might need:

• Kohler XT-6 XT-7 Service Manual – 84 Pages OEM Factory Specs
• Kohler OHC 16 HP, OHC 18 HP Service Manual – OEM Factory Specs
• Kohler Command Service Manual – OEM Factory Specs for 5-6 HP Engines

Also, if you’re comparing engine designs, the Manual Transmission isn’t the same as a Manual Transmission? That’s a different system. Stick with the scope of this manual – engine only.

What page are the Kohler CH740 torque specs on?

Pages 26–30 for head bolt torque and sequence.

Does this manual include wiring diagrams for the EFI system?

Yes. Section 8 (Electrical System and Components) includes full wiring schematics, connector pinouts, and component test tables. The EFI harness is covered in detail – injector pulse test points are on page 116. If you’re chasing a no-start caused by a failed ECU ground, you’ll find the test procedure there. I’ve used that page to diagnose a shorted fuel injector on a CH750 that had been misdiagnosed by three shops. The wiring diagrams are clean and labeled with factory colors – not the faded scans you get from copy shops.

Can I use this manual for the Kohler CH25 with EFI?

Yes, Section 5B covers EFI.

Why should I pay for this when I can find a free PDF online?

Free PDFs often skip pages, have missing torque charts, or were scanned from a binder with grease stains. This is the original OEM print, 246 pages, fully searchable. You pay for accuracy and completeness. One wrong torque value can cost you a cylinder head. I charge $95 an hour, so spending $30 on the manual saves you three hours of my time. Do the math.

You need this on your bench. Access the Factory Manual and get back to work.