My 2002 400ex is bored to a 440 and has a white bros. pipe on it. It will NOT start below 40 degrees. I really want to ride in the winter but its kinda hard to ride when it wont start...Help please?!?!

 

What size is the pilot jet? Any mods to the intake? The jet should be at least a 42 for even a stock motor.
Be easy on the throttle...the accelerator pump can easily flood a cold motor.
If all else fails...have your buddy hook up a tow strap, and bump start it. Even with a flooded motor, it should start by bump starting.

 

It hasnt had any intake mods, and to my knowledge it has the stock jetting. It will bump start but i would like to just use the electric start...its easier

 

Try the #42 pilot jet, both you and the bike will like it better.
check out this how to

 

What size jet do they come with stock? I think it is a 38... Not sure though.
Thanks ill try that and tell u the results

 

Yep, its a 38 for stock

 

Alright thanks for the help. It can sit till spring, I got about 2 and a half feet of snow on the grond for now. Its getting a top end rebuild and the carb adjusted in the spring