07 400ex changing cam

[RustyStunts]

hello everyone...i have a 07 400ex and a 450r...for some reason i cant get comphy on my 450r so im trying to get some more power in my 400ex so i could just ride it all the time...so i got a stage 2 cam for my 400ex and im wondering if i could just swap it out my self in my garadge or do i need a pro to do it?? ive done motor work before just not this...im sure i could just follow directions of line but i wanna make sure i could...the quad also has a hfm pipe so im gonna need to jet it also right? the pipe is only a slip on

[CarGuy7a]

A cam isn't that hard to do if you have mechanical ability. I did a stage 1 hot cam in mine with absolutely no knowledge of the 400EX motor. I did get a Clymer manual before doing the installation though which helped a ton.

If you have the proper torque wrenches and socket sets, that's all you need. Also make sure to use blue loctite on the cam sprocket bolts.

[togup]

the valve train components are the most frequently worked on (timing chain ,valve seals, cam upgrades, cam chain tensioner and valve lash) so get a manual and knock yourself out just remember if you have extra parts when your done your not done LOL

[ae13291]

super easy to do, just take your time so you do not mess up. if you can do a valve adjustment you can do a cam swap. make sure you loosen the cam cover bolts slow, some older quads have a tendency of snapping the bolt. and also make sure not to drop the chain down in the cavity.

here is the write up i followed
http://www.lspsonline.com/howto/400ex%20hotcam/index.htm

[RustyStunts]

sweet thank you guyz...well all I have is the cam itself so looks like I'm gonna need to buy some lube


now will I need to jet my carb or no? I have a ballance hfm pipe slipon besides that motor is stock...??????

[CarGuy7a]

Originally posted by togup
the valve train components are the most frequently worked on (timing chain ,valve seals, cam upgrades, cam chain tensioner and valve lash) so get a manual and knock yourself out just remember if you have extra parts when your done your not done LOL

Actually if he's taking the stock cam out and putting a hotcam in, he will have extra parts left over. That little spring and plunger for the decomp mechanism.

Just make sure you DO NOT drop those tiny spring and plunger parts into the motor or you're screwed and will have to take the whole motor apart.

Also you may want to get a new valve cover gasket or head cover gasket or whatever it's called.

You might have to re jet. I did have to go one size higher on the main jet. I had to go from 155 to a 160.