My friend bought a 92 LT250 the other day. It ran excellent for the first day, but he had some problems on day #2. It cuts out when he opens it up, but it runs fine at idle. We put a new plug in and it ran better but it still has a slight hesitation when you open it up and it only gets worse when the motor gets warmed up. If anyone could help us before this weekend it would be appreciated.

 

Sounds like it's running a little rich. Go down a jet size or 2.

 

If it ran fine, then progressively got worse, and he just bought it, there's a few bases to cover. Make sure the gas is fresh. May be picking up some water (condensation) in the bottom of the tank. If it sat for a while, the carb could have some clogged passages. And here's one you never catch until you're going nuts and I've seen it a couple of times: check the silencer for being plugged. They can pass air and "feel" fine when you blip the throttle, and plenty of air seems to come out, but at the same time be plugged enough that when under load and full throttle it shuts it down like you have the choke on. If the first couple of obvious things don't fix it, take the silencer all the way apart and look for a screen in the front of it all choked off or something like that.

 

It seemed to be running rich. The plug was a little black and seemed to be about ready to foul. I think we'll check the silencer also. If anyone else has any suggestions, please feel free to post them.