My brother picked up a JD LT150 with a CV15S that will only run at full throttle. The throttle moves but the RPMs stay up there... unless you slightly choke it, then it will idle down, but you have to play with the lever to keep it running. I played with the governor lever and there is no change in the RPMs.
Seems to me like a carb issue.
The elderly man he bought it from said there was a bang and there was smoke. It has sat for about a year, but a shot of starting fluid and it fired up, witht the aforementioned high RPMs.
