piston and cam

[bigbad400]

what is all involved to install a high compression piston and a cam, what kind of power could be expected and whats the average cost of professional instalation?
this is for a 2000 400ex.

[pro-rider46]

you should expect to see around 4-6 hp increase by my estimation, if you where to do it, you need to pull the vavle cover off, the cam, and chain, pull the head off, and pull the cylinder off. if the cylinder is in ok shape, take it to a machine shop to see if its outta round, and get it honed, it it is damaged, get it bored out a bit. and you will need gaskets, this should be around eh...500 with parts...

[400exrider707]

If you're mechanically inclined, do it yourself. You cant learn if you dont try. A simple cam and piston really wakes this motor up. I did a stage 1 and an 11:1 piston on mine and it made a world of difference. Not that hard to do. While its apart do a CRF 450 cam chain (same thing as heavy duty cam chain, but much cheaper) and do the thin cometic head gasket (to bump compression a little more) and the thing will rip. Not that difficult to do. No tearing into the bottom end really. Get a manual and you can do it!

[bigbad400]

thanks guys, that dont sound too bad. i think i can figure it out. not to expensive either.

[400exrider707]

Originally posted by bigbad400
thanks guys, that dont sound too bad. i think i can figure it out. not to expensive either.

Make sure you do that cam chain while its apart, its a vital component that is known to fail on these motors, and what is another $35 when it comes to your motor?

[bigbad400]

oh ill for sure change it, the good heavy duty one aint to much more is it?

[400exrider707]

Originally posted by bigbad400
oh ill for sure change it, the good heavy duty one aint to much more is it?

Stock 400ex cam chain is something like $90

Heavy duty DID is something like $115

Stock CRF450 cam chain (same as heavy duty and in fact some motor builders sell them as HD ones for a lot of mark up) is $35

Get the CRF450 one.

[bigbad400]

hey thanks guy your alot of help you just saved me like 300 in labor and another 100 in parts, im also getting a stage 2 cdi and velocity intake kit. that should top this beast off untill i get another itch and need the 416 or 440 kit. any suggestions on the cdi,s? or is there anything i should have to do this stuff, special tools, anything at all i should know? you bean alot of help bro i appreciate it.