ok, BBK, stroker, hot cams stg 2, P&P, K&N, FMF powerbomb/powercore4, STOCK carb...

I was thinking of a 41mm FCR from a YFZ but is there any others I should consider? also would one from a different bike be more suited to the way the throttle cable pulls on the 400ex. thanks.

also the guy who built the engine reccomended a YFZ's 41mm FCR, will it be a huge noticable increase. say if a certain YFZ is always a couple bikes ahead of me, after the carb ill win. and no its not rider weve switched back and forth and its always the same practically every run. once I just lifted the front end straight up and went nowhere and of course she got a HUGE lead on me, but every other time they are similar results.

 

just bringing it back from pg 2 to top of pg 1

 

anyone??? anyone?

also I was wondering if the 04 and 05 YFZ had 39mm carbs and the 06+ had the 41mm's

 

I have a 440 stroker with an fcr 39. It is the carb from an 04 yfz including throttle cable. The engine is built for torque with a web 450-451 cam. I just put a hmf full system on it, also. It runs killer, but doesn't have alot of top end. The engine isn't meant too, though. With a bigger carb it would probably hurt the power curve.

Do you want a top end revver or a torque monster? That would sway which way to go with carb size.