400ex Carb On A 300ex??

[COOTERGUY]

OKAY I KEEP HEARING ABOUT ALL THESE PEOPLE,EVEN SOME OF YOU ON THIS SITE LISTED EITHER ALLREADY HAVING DONE THIS OR WAITING TO GET A 400 CARB SO YOU COULD. IS IT REALLY GONNA MAKE A DIFFERENCE JUST GOING FROM A 32MM TO A 35.5MM. DOES THE CARB FIT IN THE BOOTS ALLREADY ON THE 300 OR DO YOU RUN 400EX BOOTS? ALSO HOW DID YOU JET IT TO START OUT WITH?

[cals400ex]

the more mods you have done to the bike, the better it should work. yes, going up a few mm's is a decent amount. i am not sure where you should start jetting at but i would start similar to where a stock 400ex is jetted. you will need to tinker with it for a bit too. the carb is a tight fit on the air boot. i hear you can heat the air boot up and with a little force the carb will go in. this will stretch the boot a bit so next time it should easier. if you don't like that idea just pick up a 350x air boot and that will do the trick. i sent you a pm too.

[COOTERGUY]

HAS ANYONE ELSE TRIED THIS??

[dirtmomma]

Yes I'm in the process of trying this now, just waiting for my head to get done & already did the air boot deal, I boiled my stock one for a minute then shoved it on there, just need to get a little bit bigger clamp. As far as jetting I'm starting w/ a 41 pilot (I;'m pretty sure :)) & a 150 main, but won't know anything till we get it up & running of course, I race w/ a gal w/ this same setup & her quad pulls really nice, got to ride it at the last race & was impressed w/ it. I will try to post how it goes w/ mine ;)

[COOTERGUY]

NOW THAT IS JUST WHAT I WANTED TO HEAR LOOKS LIKE I WILL GET ME A 400EX CARB ON THE WAY AND GET ME A BUNCH OF JETS TO TUNE IT WITH. LET ME KNOW HOW THE DEAL WORKS OUT FOR YOU.