Alright so my friend has an older 2wd ltf250, and it has the weird vacuum diaphragm carb on it. It will idle fine, and it runs pretty good in the upper rpm's, but once its hot, if you ride it and then let it sit at idle for more than 10 seconds or so, it is super touchy when you try to get on the throttle again, and it almost always dies. the only way to get going from that point is to "tap" the throttle a few times until the engine starts to rev up.

and ideas?

 

Yeah, those cv carbs suck lol

The throttle is operate by engine vacuum, so if the air cleaner is dirty or has holes in it or there is something amiss anywhere before or after the carb, the silly thing throws a fit. You're just going to have to start digging around checking everything and anything that would affect engine vacuum on the carb. Including that diaphragm. Cant have any holes or cracks in it and the seal has to be good. The slide should move up n down easily too.