I want a 426 kit for my 400 but all ive found so far is 440,s. Any help would be much appreciated.

 

ive seen 416 kits built by curtis sparks, but i never heard of a 426 kit

 

Call Marcum's ATV, and talk to Terry. He's extremely knowledgable on motor mods for the Hondas.

He will also beat any price on aftermarket stuff for them. 1-877-264-3409

 

Order a piston man and gasket set, if you go all out consider getting new head bolt's cause of all ready being torqured down once and the increase in power and vibration they will break (say hello heli coil) and don't forget about new exhaust gaskets. You don't want to crack your headpipe.

85mm piston stock 400
86mm 406
87mm 416
88mm 426
88.5 432 alot of guy's sell this piston kit with sleeve as a 440 but it's not you have to overbore it and get a 89mm piston to have an actual 440
89mm 440 you need to resleve your cylinder

Any bigger you start to getting case boring and stroken it.

9.8:1 compression stock
10:1 or 11:1 and higher?
Go with the 11:1 if you can afford a good cam and port it. (400xr cam is not a good cam. No noticable difference when driving it, there is just a very slight increase in top end power so don't wast your time, spend your money on something else)

Porting and having your head flowed with a three or five angle vavle job really increases the power alot also. You'll need to buy new valve ceet's. Oversized headpipe will help also.

 

Go to

www.LRDperformance.com
www.sparksracing.com

Both respectable engine builders and both offer those bores..