I have a small 450 Bobcat with a Kohler 18 HP engine. I have had it at the dealership twice to fix this problem--seems to be better for awhile--then back to the same. It will run about half an hour-less on hot days or under heavier use. It gags a bit-like gas running low--then quits. I let it cool down but to start then I must use ether in spark plug hole. If I run for short times it is fine. If it does not gag out and stop then it will start normally the next time. They have put in new fuel pump and thought intake hose collapsing when hot. Doesn't matter-still the same. I am contemplating a new engine but that is costly and I don't know if I could do the switch out myself--or if it would help. It is an early '90s machine. It is air cooled and when it does stop it seems to be fairly hot at the back when I open it up.

Any help would be great but I am not optimistic.

thanks

John

 

First I would try loosening the gas cap and see if the problem continues. If it solves the problem you need a new cap. If that did not take care of the problem I suspect the coil is going bad and does not work when it's hot.

 

I'd definitely do the fuel cap check. If nothing improves, check for spark when it dies. If no spark, your coil may be bad (single cylinder or twin?). Is the muffler rusted and blowing exhaust into the engine compartment? If the exhaust isn't routed out well, the engine compartment may be getting too hot, causing the fuel in the carb to vapor lock.

 

I appreciate both of these responses. It definitely gives ma a direction to pursue. THe more I think about it the more I lean towards the heat in the engine compartment and vapor lock. I once fought vapor lock on a vacation to the Rockies and now that you jog my memory--this is very similar. Thanks again for giving me some Hope!