Trouble 38hp EFI Kohler


LawnSite Silver Member
I'm having 3 different issues when my 2014 Exmark with 38hp EFI Kohler.

Model numbers:
Exmark LZX980EKC726
Kohler ECV 980 V serial 4333803881

1. Current issue is the rpms are revving higher than normal operating speed. They are varying with or without blades on. The throttle switch is in low and it's still revving high. Is it a bad switch?

2. Next issue has happened many times but it's inconsistent. Rpms go high and low. Only by a few hundred rpms though. This is with blades on or off as well. It's just running rough. Changing spark plug helped for a little while but back doing it again.

3. I've had a few episodes where the mower in a property will almost stall but then regain power. It will do this a few times or one lawn it did it probably 25 times. But now it's been 3 weeks and that hasn't been an issue.

Thanks for any help

Not sure if these are different issues or all related. I've done the simple things that I know to do, check wires, connections, etc.


LawnSite Senior Member
Near TMI
I know zero about fuel injected engines but I would check all of the simple things first; fuel quality and supply ( siphon fuel from tank and inspect screen in bottom if it has one), fuel filter, loose connections and chaffed wiring. Good luck.