400ex valves and timing

i have a 2001 400ex, i have it tore down putting piston in it right now. how do i know where to put the timing when it goes back together? what marks do i go by?

also, how do i know when to adjust the intake valves and when to adjust the exhaust valves? this is the first time ive done a 4-wheeler.

nvmnd yall i went to ex tech thanks alot though

i still need To know about timing? i heard sum1 say sumthing about it is electronic. wuts that mean? if not how do i set it?

[Leo]

the ignition timing is automatic / non-adjustable..

you must however make sure that the camshaft is properly set to the crank or you risk having the valves contact the piston..

Leo

i know i sound stupid probably, but how do i know when they are lined up? i it like a car, the mark on the cam sprocket straight down and the mark on the crank sprocket is straight up so they line up?

[Leo]

the "T" mark on the flywheel goes in the window on the side cover..

the camshaft has 3 lines on it.. 2 go even with the top of the cylinder head with the third one at the top..

take a look at the cam gear and you'll see what I'm talking about..

pay special attention to the spring / plunger in the cylinder head, you don't want to loose them!

Leo

Should the marks be on after tightening down the chain tensioner as well?

Daren

[Leo]

yup, all the tensioner does is take the slop out of the chain..

did you retract the tensioner before tightening it down?

Leo

I did not retract the tensioner but just took the whole thing out when changing my head gasket. In the process of doing that, I found that my chain came off the bottom sprockets.


Daren

[timewass]

Suggestion: Pay $30 for a service manual

[TheX1992]

oh yes make sure you retract your tensioner. on my 250x i forgot to do that and it was all the way out when i put it back in. i snapped my cam chain. and to do your timing, you should have 2 holes that screw off, well caps, on your left (mag) cover. unscrew both of them. get an 11/16th socket and put it in there. get a flashlight and look in the smaller (left) hole. now it takes 2 people to do this. make sure the cam sprocket lines are paralell to the head (and the cam lobes facing down, not up). there should be a little T type thing in the little hole. turn the socket (which turns the crankshaft) until you find it. it will be a little hard to hold on to because thats where TDC is. keep the T in the center hole and have the other person put the cam on the chain and bolt it in. make sure to put oil on the lobes. reassemble and see if it starts.

Hope this helped you a little bit.

[400exRacerX]

First you take the cam and put it on the head with the lobes facing down. Then line the 2 timing marks on the cam sprocket parrallel with the top of the cylinder and make sure the middle one is pointing up. Then put the chain tensioner in.