I've got a 1991 KLR 250, the carb is stock, and whenever i turn on the gas and take the bike off the kickstand so it's upright, gas leaks out of the overflow hose underneath the carb. It pours out pretty good. I'm not good with carbs at all, and im just wondering why its doing that. I was planning on taking it in somewhere to get checked, but if i can fix the problem myself, then that would be great.

 

Welcome, Sounds like your float is stuck. Try rapping on it with something soft...screwdriver handle, etc. If it still leaks pull the float bowl, see if the float moves. If it does, remove the pin, pull the float and needle. turn on the fuel for a few seconds- sometimes that will flush out the seat. If the float won't move, spray carb cleaner on the pivot and gently move to free it up. Possible further disassembly and cleaning may be required. Get a manual, it's not too hard to do.

 

Yep, I agree, theres something holding the float needle and seat open. Its usually some dried out crud from evaporated gas.