Kohler CH-25 throttle

[Rick_Taylor]

Has anyone else had a problem with the throttle control on the PT-425? It's definately a Kohler problem. The PT is the third of these engines I've had (others were on two Kees ZT mowers) All three have had sticky throttles. All machines cleaned thoroughly after each use.

I can't seem to pinpoint what exactly is sticking. The cable moves it's part of the linkage just fine, but from there it's a function of the engine governer. I've been resisting taking the whole linkage apart, but the stickyness appears to be right at the carb butterfly shaft. Of course I've sprayed lots of carb cleaner on the linkage many times, to no avail. I'm lucky in that I have two, one to take apart and one to use for reference. Just thought I'd ask first. Any ideas will be appreciated.

 

[bmkar]

Some one w/ a Kohler will chime in here,I know, but in the mean time...I recently experienced a "stiffening" of the linkage on my Robin...I disconnected the cable where it attached to the engine and found the "stiffness" on the "friction" linkage that attaches to the butterfly. I think its purpose is to "hold" whatever setting you dial in. I just backed off the nut a bit to bring back the "freedom" of movement that I had originally. I took the opportunity to lube the cable so that corrosion in the cable wouldn't be a reason.

Does your Kohler have a similar "friction" link to the butterfly?

 

[Rick_Taylor]

I don't think so. I think it just uses the friction from the throttle lever.

 

[Rick_Taylor]

The symtoms I'm experiencing are a failure to accelerate and not coming back to idle. By pushing on the lever sticking out the back (connected to one end of the spring), I can cause it to rev up or mostly idle down. Of course the throttle control has to be in the correct position. Most of the time when I shut down, I get a LOT of dieseling which is often caused by idle speed being too high. I remember someone else asking about the run-on at shut down. Maybe their throttle is also sticking. Throttle down problems always show up first.