08 yz450f cam chain issues

[sk8bd117]

I am doing a new piston and sleeve on my bike. When I'm trying to put on the new cam chain over the cams, I simply just do not have enough chain to get over them. The tensioner is not in. And I have triple checked the guide positions. It is seated on the crank sprocket. I even tried to get the old chain back on, and couldn't get that one over the cams either. Anybody have any clue.?

[Mxdude91]

i have to have the cams out of place to get the chain on and then put them in place and check my timing then put caps on.

Edited March 24, 2014 by Mxdude91

[grayracer513]

The front chain guide is held in place at the bottom by snapping into the V-shaped pocket in front of the crank.  At the top of the cylinder, the guide has two pegs that sit in a slot across the front of the cam chain tunnel, and clamped in place by the head. 

 

An easy mistake to make while trying to get the head in place is to knock the guide back out of those upper locating slots.  When that happens, it sits back too far and interferes.  Might be the problem here.

[sk8bd117]

I even took out the front chain guide, and tried to see if I could get the chain on the cams with it out. Still no luck. I'm stumped on this one

[grayracer513]

The chain is normally not long enough to be lifted over both cams with both in place. What you have to do is to place the exhaust cam and locate it into the correct timing position, then place the intake cam in the center of the head between the two cam bores and get the chain over it, then roll in down into place and verify the timing. 

 

You weren't able to remove the front guide without removing the head, were you?

[sk8bd117]

Thanks grey. I'll give that a shot when I get home today. And no I was not able to pull the chain guide out without removing the head

[grayracer513]

 

no I was not able to pull the chain guide out without removing the head

 

A good sign.

[sk8bd117]

Still can't get them on. Even if I take out the chain guides, I still can't get it over the 2nd cam