Kohler running rich when under a load

[ghost1]

Have Kohler Command Pro 26 with EFI. Starts and runs great on idle or full throttle, however, when PTO engaged, engine starts to stumble, blow black smoke and loose power. As soon as PTO disengaged, engine begins to run normal again. Replaced plugs and they were very full of soot. Reset governor (per repair manual) and no change.

Any suggestions would be appreciated.

 

[ILENGINE]

some of the CH26S engines had a problem with poor harness ground. look for the grounding wire that could be connected to either the starter bolt, a blower housing bolt, or something of that order. There was problems with the stainless steel loop connector that wouldn't maintain proper ground when the block or mounting bolt started to corrode. There is a kit available to convert the engine from stainless steel to copper coated terminal.

May be associated with a fault code 31 or 34

 

[ghost1]

That makes sense as sometimes when cutting grass, it will act as though a switch was thrown and it will clear up and run great.. then after a couple of laps, will start acting up again. I'll check grounds and advise.
Thanks again

 

[ghost1]

That makes sense as sometimes when cutting grass, it will act as though a switch was thrown and it will clear up and run great.. then after a couple of laps, will start acting up again. I'll check grounds and advise.
Thanks again

Amazing something so insignificant can cause so much grief. Yep, it was the ground. Cleaned connections and runs like a new one. Learned something today.

Thanks ILENGINE