Whats a 400ex carb on my 250x gonna do?

[2fastandfurious]

What performance difference am i going to gain with replacing my stock 250x carb with a 400ex carb? Thanks,
-Ben
Do i have to buy a different size air boot as well?

[airheadedduner]

What size is your stock carb?? I think the 400's is a 35mm. Now there is such a thing as over carbing a motor. When you get too large a bore the motor can not produce enough vaccum to give the fuel charge sufficent velocity for good low-mid performance.

You may get better top end but most likly your low-mid will suffer so bad that it will not be worth it.

[TRX_Thumper]

yeah unless your runnin a big bore kit or somethin i wouldnt mess with it

[Jimmy Lee]

Id seriously doubt it would work!! The carb for the 400 is made to feed a larger displacement engine!! time and money wasted in re jetting and tryin to get it right!!! really would be a waste....just buy a pipe filter and jet kit and youll get plenty of performance!!
JJ