my friend has a 03 kfx400 and he wants to get a bolt on 440 kit comes with cylinder and piston and all. also he bought the cams and he got to reading the cams and they told him they he has to use the cams with the stock piston and stock springs. well i was under the impresstion that you could put the 440 kit on with the cams and with aftermarket spring. Thanks

 

what type of cams are they,whats the lift and duration..?

 

finally got the cams in and it did not run all that well so we couldnt figure it out so my cousin got to lookin and he found out you had to put spacers in for the valve clearence instead of the orignal style of valve setting like on a raptor so the shims saved the day and needless it say it ran a whole lot better hund right beside a piped and jetted raptor with a open lid and geard for racing but the problem with all the cam issues is the valve shims getting the valves set runs alot better beats the z that used to beat it by 4 quad lengths before bad