My 400ex is stock right now, only have a Curtis Sparks pipe and Ignition advance key, CDI, K&N and rejeted carb. I want to have a 426 kit for it, I dont want to lost a lot of bottom.
Were can I buy the best performance value 426 kit, I don't want to buy a new carb right now.

Thanks

 

check out http://www.powroll.com they may have something you are interested in.

 

Buy an 88mm piston & rings from JE or Wiseco, then you will have your 426 "kit".