How to retime a 400ex

[Dobber]

I was having a problem with my 400 thought it was timing so i attempted to move it in doing so i forgot to release the timing chain tensioner and attempted to start it well you no the rest its way off now

[fauxamish]

Remove the 2 plugs on the stator side (left side when you are sitting on the bike). The bigger one allows you to turn the crank counter clockwise using a 17mm socket. The upper is an inspection hole so you can see the markings on the flywheel. Turn the crank until you see a line followed by a T. This is the mark for top dead center (TDC). If you bike was in time, the rockers should be loose, but if your timing is screwed up, who knows... Anyways, pull the valve cover so you can get at the cam and timing chain. Take out your tensioner also.

With out dropping anything into the engine, take out the 2 bolts holding the cam chain gear on the cam. Put the lobes of the cam DOWN! Then, the cam gear goes back on with the 2 lines parallel to the head. They should look like this -- --. If the crank is at TDC and you get the gear/chain on the cam with the lobes DOWN and the -- -- parallel with the head, you will be in time.

Your timing chain tensioner should have released as soon as you pulled the screw driver out. Test the tensioner to make sure it still works properly. With it out, you should be able to push on it and it should not move. If it moves, replace it with a new one.

Hope this helps. I wrote all this from memory, so I think it is all correct.

[dariusld]

I have a bad memory. You don't have to remove the cam gear from the cam, do you ?

[fauxamish]

I don't remember if you can get enough slack out of the chain or not to make it skip a few teeth. I have never tried to "retime it" this is just from when I rebuilt the top end on my project bike. Everything was already apart...

[mcgrath]

I know I can skip a tooth at a time on mine. Not sure if I should be able to but I can... and have.