Engine Surge 20 HP Kohler Command

[Leo Rabon]

Need Advice on this. I have a Cub Cadet GT 2000 with a 20 HP Kohler engine. I purchased the GT in June 2011. The engine has 27 hours on it. Last week, I went out to mulch and pick up leaves in my yard; started the tractor and drove approximately 100 feet at 1/2 throttle (blades not engaged) to get to my starting point. I stopped (no throttle adjustment) to pick up a limb in the yard and the engine started surging. I immediated adjusted the throttle up a bit and the surging stopped. I worked another 3 hours in the yard and had no other problems. This happened to me one other time at about 10 hours on the engine but the surging only lasted about 5 seconds and stopped.

The engine has performed perfectly except for the two times the engine has surged. I only run 100% gas in this tractor (no ethanol). Is this just a fluke or do I have an engine problem in the making????? Any advice would be appreciated.
Leo

 

[RandyT]

Could be a temperary blockage in the carb that is clearing itself or an overly sensitive governor spring.

 

[ToadHill]

My 23hp Kohler surges when ever it doesn't have a load on it. When I just drive from one place to another it surges, as soon as I load it by engaging the mower deck it stops.

 

[Leo Rabon]

Thanks Randy and Toadhill for your replies. Since it is so new, I guess I need to wait until the problem gets worse as taking it in for service probably will not help since it probably will not duplicate the problem in the service department. With only 27 hours on it and another 3 years to go on warranty, I should be ok.

Leo

 

[RandyT]

My 23hp Kohler surges when ever it doesn't have a load on it. When I just drive from one place to another it surges, as soon as I load it by engaging the mower deck it stops.

Partially clogged idle circuit jet in the carb. When an engine is running even at top no load the engine is running on the idle circuit of the carb. when you put a load on the engine it transitions to the high speed circuit to get its fuel.

 

[harleyizy]

sounds to me as as minor carb adjustment on high and low jets. owner's manual usually tells how to make this adjustment. mine changes in the fall and again in the warmer months. i may be wrong but i think it should be done when engine is warmed up and a load on it. like i said, i may be wrong. correct me if i am.

 

[RandyT]

There may be an idle jet adjustment screw but no high speed adjustment. Most likely neither is adjustable and the carb will need to be removed and cleaned, and even then that sometimes won't do it due to small passages that you cannnot get clean.

 

[harleyizy]

yer right randy. according to kohler's website "engine runs lean,(indicated by misfiring, loss of speed and power, govenor hunting, or excessive throttle opening.) possibe causes, low idle fuel mixture is improperly adjusted, float level too low, idle hole plugged in fuel delivery channels. conclusions are; adjust low idle fuel needle(some models), adjust float according to steps outlined in repair kit installation instructions. remove low idle fuel adjusting needle. clean main fuel jet and all passages, blow out with compressed air."

 

[JTKub]

This could also be a simple as a batch of old or contaminated fuel as well.

I know anything is possible, but it seems unlikely the carb is plugged with debris given the machine is new and Cub/Kohler puts a huge inline fuel filter on these machines.

Joel

 

[rcbe]

Agree with JT's take on carb condition but would still get "on record" with yer servicing dealer - stops the "you've had that machine a long time now" response down the line if problem gets worse.