Why wont it start? Is it the Timing? 426....

[Da300EXer]

Ok, We just got my cousins 426 together and back in the frame. It has JE 426 piston, 10.8:1 compression. XR400 cam.
We put it together almost without a problem.......
Key word, almost!
We put the cam in, and we put it at Top Dead Center...
We put the cam lobes facing down....
We put the sprocket on, and we put the chain on the sprocket no problem.
Heres the almost....
When I put the cam chain tensioner back in and the cam chain was tight, the marks on the cam chain sprocket no longer lined up exactly....
It was not off by more than a whole link in the cam chain, so, I couldnt get it to be exact, it was either too far forward or too far backward, no matter what I did.
I left it too far backward, and put it together, just to see, becasue I didnt know what else to do.
Now it wont start. It cranks over and it pops, but it wont start. We tried it with an aftermarket CDI and the stock CDI, still no go. The battery is fully charged, we even tried jumping it, still no go....

We arent sure if the quad MAY have a timing advance key....... MAY, we dont know.....
Would that cause the timing marks to be off? What should we do? If it does?

If there is no timing advance key installed, what else is causing the marks to not line up? stretched cam chain? worn bottom cam chain sprocket?
Is the timing problem the reason the quad isnt starting?!?!




Any advice would be greatly appreciated! Thanks in advance

[dj416]

take the cam out and try it one more time, the first one me and my friend rebuilt we had the same problem, poping and stuff. we took it out and put it back in and it seamed to work right. make sure that its the right mark, there are a few on the flywheel and it really easy to put it on the wrong one

[kc 300EX]

Still wont start... we took out the cam, moves the sprocket forward one link.... out of ideas

Any one think they can help?

If not its gonna have to go to the Honda dealer! Nooooooooooooo, please!

[Bill Fuller]

Have you checked for spark?

[Bill Fuller]

It's ok if the marks are a little off,but not much.Are you sure the valve lash is set properly?

[dj416]

when u say u got it a top dead center witch mark on the flywheel did u line up with the pointer?? there is a couple. if u just got it a tdc without lookoing at a mark it could be 180 degrees out of time

[Castor-426ex]

you have to reset the tensioner....did you read in the manual?

[RAPTORAZ]

I had the exact thing happen to my EX upon completion of my 416 and cam install. Mine ended up being the White Brothers rev box. I had my cam out three times before I decided it wasn't the problem. I even checked the spark. It had spark, just not enough. I put the stock box back on and it fired right up. Talk about a coincidence. My box dieing at the same time I put in a piston and cam. :confused:

[kc 300EX]

Weve done everything by the manual.
We definetly have it at the correct TDC. We lined up the "T" on the fly wheel.
We checked and we have spark.
We are now going to start taking parts off another running 400 and see if we can diagnose the problem that way.... We dont know what it could be though

[kc 300EX]

bump.... any suggestions?

[Bill Fuller]

Have you tried having some one pull you to try and start it?