I got a klx250sf from a buddy of mine who asked if i could fix it and when i got it, it only starts and stays running with the choke on but as soon as you put the choke in or try to give it any gas it dies immidently.. I cleaned the carb completely and put a new spark plug in it but still has the same problem..

It only has 50 miles on it but he told me it was sitting for a few months with fuel in it.. I dont know what else to try so any help would be good.
Thanks

 

Welcome to the forum.
Here are a few thoughts. Turn the idle adjustment up a little and see if that helps. My '06 when stock needed to warm up quite a bit on choke, and even after, before I could blip the throttle.

Check the pilot (idle) and main jets again. They may be gummed up. If no success on cleaning the jets, consider replacing them.

Empty the gas and refill with fresh.

If only 50 miles, isn't it still under warranty? Take it to the dealer.

Try some fuel additive like Sea Foam. It can sometimes help in a situation like this. Put some it with the fresh fuel, run the bike for a little bit, then shut down and let it set for a while. Repeat another time or two.

 

Re clean the carb, and try it with the fuel cap open to make sure it's not a venting issue.

 

Agree^. Drain the carb bowl, refill with fresh gas. See what your plug tells you.

 

hey im new here and had the same problem at 2000 miles had to limp outa the woods on choke turns out the airbox drain tube has a plastic plug and mine broke jets full of dirt wich also speaks to trouble with air filter fit but a cleaning of all jets and carb did the trick with a much better plug and double check on filter placement good luck