My 03 400ex has a problem. When I add gas with the choke on, its good. But when I turn the choke off, I will try to add gas and it dies. What can the problem be?? Thanks for your help.

 

A lot of these "it won't run without the choke on" posts lately......

You are getting to much air for the amount of fuel. Most likealy a clogged jet, but could also be an air leak. Check the air filter, and the boot between the airbox and the carb for leaks. (Remove the air filter, hold your hand over the opening and crank the engine a couple of times. It should suck on your hand and not lose vacume readily if there isn't a leak.)

 

Must be a lot of bikes just coming out of mothballs, after the summer off (at least here in So Cal.)

Likely clogged jet or sticky float valve.