My 1989 TrailBoss won't idle. I've adjusted the idle the whole way and it still stalls. When I try to ride it, it bogs down on the low end, takes off....then runs fine at 1/2 to full throttle. It has done this before when it got wet from crossing a creek but always dried out quickly and ran fine. This time, I know its not wet, I haven't ridden it for a month and its been in the garage. I have cleaned the K&N air filter and replaced the plug. Before I remove the carb and clean it, do any of you have any other ideas?

 

Rebuild your carb or at least check it out. The needle and needle jet along with the float valve are likely worn causing a rich condition. Older 250s also tend to get base gasket leaks on the left side unless it has a new style gasket installed in it. While the carb is off check the boot that adapts the carb to the engine they crack after a while. Make sure the oil and throttle cables are adjusted correctly.

 

Charlie, Thanks. I'll take the carb off tomorrow. When I bought it about a year ago, it had sat for several years. I removed the carb, diassembled, and cleaned and it made a big difference. The good thing about it sitting was that it is in great shape. Is the rebuild kit for this carb something that the dealer would have on stock? If it is, maybe I'll go get a rebuild kit in the morning. The last time I had it apart, nothing was worn. A good cleaning did the trick. I'd like to get it running right without spending much. I'm selling it (or almost giving it away) to a family member.
Have you had any problems with the air box cracking on these? Mine cracked where the lid bolts were attached at the corners. I fixed it with some 5 minute epoxy and it seems stronger than ever. Thanks again for the help. I'll let you know how it turns out.

 

I took the carb off and cleaned it. I found a clogged pilot. I couldn't see light through it or even blow through it so I got a bristle from a brush and cleaned it out. Put it back together and it runs better than ever. I got away without a rebuild kit.