ok...jus biult another 400ex. got a 415 je high comp piston, stage 1 hotcam, HD hotrod crank, and jetted it from a 150 to a 170. its got a new k&n air filter, and a open air box.

my question is when you first start it (cold) it will only start if its not choked. you can goose the throttle, smackes rev limiter, comes right back down. its really responsive!!! after it warms up it will run good, idle good, and start good. but it runs funny at between 1/4 throttle and 1/2 throttle. when its in a gear or just me crackin down on the throttle, it just dont do like it should.

any help would be great.

 

and i leak gas sometimes... my floats look to be clean. and so does the carb??????