Im wondering other mods to make my 400 have more power and acceleration. people always say 400s cant beat 450s and all so i want to make mine be able to beat 450s and other bigger atvs. Also what can you take off for less weight? Thanks for all input.

 

I think you will like this read. Honda TRX400EX "Low Budget" Project ATV
Great bang for your buck tips. You may not beat a 450 but you will improve your ride and fun factor greatly for sure.

The 450 are motocross motors they are just in a different technology class.

Even if you can get the 400 air cooled up to 45hp like the stock 450s in some way, you would lose your reliability and be sitting on a hand grenade with the pin pulled out.

 

I just want to be running close with them In 300ft drag racing. Ill look at it thanks. How can you get the besr acceleration out of it. Basically just let it breathe every way possible?

 

Unless your willing to tear into and and have the head ported and polished and install a high compression piston your not going to be able to compete with a 450. Even then if it has any mods what so ever you will still be left behind. You might as well use that money to purchase a 450 if that's what your after.

Other than that the tips in the article are the best ways to get performance out of a 400EX.

 

i already have the head ported and polished and a high compression piston.

 

Then you've stretched her about as far as you can. A little further than most are willing.