Originally Posted by MarkSF
What could be happening is that the whole mechanism is stiff enough that you can't feel the idle position, maybe combined with a weak spring. Consider lubricating everything in the throttle mechanism.
On heavy machinery it is usually the size and age of the cable, they are LOT bigger diameter than the smaller ones on the boats, and they are just really stiff in the sleeve. The ones I have had the same thing happen with on a boat were most likely in need of lube in the cable itself, and the throttle mechanism. The reason I did not mess with it was because being stiff kept it from being an issue about turning itself off unexpectedly LOL. If I had lubed everything up, then I would have had to fix the spring and the little detent, and it was not a boat that was mine, except one time, and that one was getting new everything as soon as it got home.
I would certainly not like the motor to go off without permission, that is not fun.