i was thinking about gettin a rev kit for the 400ex. big gun makes one that i saw and was wondering if i needed a new piston if i got a rev kit. my friend told me that i would need one if i bought a kit. anyone out there have a rev kit in their 400? thanks

 

i don't see why you would need a new piston. I heard Big Gun and White Bros Rev kits are not too great. I heard Electrix is the best for a 400ex.

 

do you no where i can get an Eletrix kit from? i can find it when i do a search. thanks

 

I have a WB rev box on my 400ex and I have absolutly no complaints, it starts right up without hesitation and gives me the extra revs just like it should.

 

Never heard anything positive about a White Bros or a Big Gun rev kit. If you have a stock motor, don't even bother with one at all. All they do is let your engine rev higher where power is already dropping. These motors come with a rev limiter for a reason.

If you already have your heart set on one, get GT Thunder rev box.

 

we got a big gun but it is on a 440 stroker