400ex rebuild need advice

[exrider2001red]

well i found this 440 kit on e bay with stage 2 hotcams and i was wondering if i should go with the 11.1 or 12.5.1 i dont really know the difference between the too. i want to run pump gas though also will i notice a whole lot of difference in power between my motor now and once i put the 440 in mods listen in sig any help would be very much appreciated

[Big - D Racing]

run the 11:1 with the 12.5:1 you need to run race gas, and of course you will notice a big difference. 11:1 you can run pump premium gas. Make sure you have a good exhaust.

[espergre]

go with the 11:1. Cheaper gas and safer engine wear wise. Dont buy a 440 just because its the biggest out there. Research the 416 and 426 options. With the 440 you need to get a new cylinder sleeve pressed in. It is cheaper to just bore your existing sleeve. Another option being that you allready have a stage 1 hotcam is to just get a 11:1 stock bore piston. I run that setup and it trashes stock 400's and iv beat down a few 450's. With the 11:1 stock bore piston you could do all the install work yourself if you are mechanically inclined and save a ton of money and still get big gains. GOOD LUCK

[exrider2001red]

im only going with 440 because i found it on ebay for less then 300 bucks with the cam and all that is needed. i can probly do most of the work myself exept for boaring it out ill take it to the school the principle does it all the time on bikes

[AtvMxRider]

Originally posted by exrider2001red
im only going with 440 because i found it on ebay for less then 300 bucks with the cam and all that is needed. i can probly do most of the work myself exept for boaring it out ill take it to the school the principle does it all the time on bikes


You can get 416 and 426 kits for less than that with a cam also

[XXXRACER165]

Jack LaLanne = 440 power on an EX. If you run the right products with your 440 kit you'll be making 40+hp