View Full Version : 28 H/P Kohler EFI

06-06-2009, 10:56 AM
Anybody experience this problem with a CH745S. Starts fine. Idles fine. High speed - no load, engine surges violently. Engage blades, engine run fine. You can have blades engaged and reduce throttle to idle and engine wont stall. It will also accelerate cleanly from idle to high speed with blades engaged. No codes in memory (of course not). Gov adjustment has been verified and spring has been tried in different positions. When running, gov action/strength was compared to an identical unit. Seems the same. If the idle speed adjustment screw is turned in to various RPM's there is no surging. Overall condition of engine is good. 40psi on fuel rail. Has had fuel filter serviced regularly. Sometimes, I just hate advancements in technology.

06-06-2009, 03:29 PM
What is the high speed no load RPM set at ?

06-06-2009, 03:34 PM
3750. Tried varying rpms. Surge kicks in at 2300. Adjusted gov as outlined in manual. I have a feeling it's a fuel system problem.

06-08-2009, 03:54 PM
Are you getting spark on both cylinders? If there are no codes and you're getting good spark on boty cylinders I would initialize the throttle position sensor. Instructions for doing that can be found in section 5B of the repair manual pages 5B.9 and 5B.10. The repair manual can be found at www.kohlerplus.com under service literature.

06-08-2009, 09:06 PM
That was done after the governor adjustment was performed, but thanks for the input. I leaning toward possible air leak somewhere, but I 've seen an EFI run fine with one intake gasket sucked 3/4 in. If there is no leak, I think the TPS/manifold assy will be the first waste of money. I don't believe it could be both injectors. This just started happening.

04-27-2014, 08:49 AM
What was the issue? I have the exact same problem with my machine.

04-28-2014, 09:09 AM
Good luck here, that was like 5 yeas ago.