I have a Kawaski FH601V engine on a Bunton riding mower that I can't get the throttle to operate correctly on. If the engine is started with the throttle in the idle position the engine will idle correctly and speed up when the throttle is advanced. The problem is the engine will not slow back down when the throttle is decreased. The only way to get the engine to idle again is to shut it off and restart with the throttle in the idle position. Any ideas of what is wrong? Thanks in advance for any help.

I have a Kawaski FH601V engine on a Bunton riding mower that I can't get the throttle to operate correctly on. If the engine is started with the throttle in the idle position the engine will idle correctly and speed up when the throttle is advanced. The problem is the engine will not slow back down when the throttle is decreased. The only way to get the engine to idle again is to shut it off and restart with the throttle in the idle position. Any ideas of what is wrong? Thanks in advance for any help.

Any chance that it's been overheated due to old dirty,low oil? The governor thats's inside the motor on that model can get melted in the big plastic housing part that the governor balls ride in these ramped slots.I've seen that happen on one that had oil leakage past the breather cover,and the oily grass buildup plugged the cooling fins adding to the overheating.It made the governor really unresponsive and acting weird.Just something to consider.
Hope this helps.
take care, Steve

bad throttle cable or could be an air leak. Check the carb see if its loose or get some WD-40 and spray it around it (don't soak it) and see if that helps before breaking into the engine. do the easy stuff first not the hard stuff:cool:. the engine should either rev back down to normal or it might rev up a little.

Does the engine idle back down at all or does it stay reved up, could also be a dirty govenor spring that needs some spraying off with the old garden hose.