Cam Chain Issues ?

[Englishman]

So what do you think is or has gone on here?

This is the Cam Cover on the inlet valve side

Either:
Cam chain tensioner is not doing its job,
The cam chain is at the end of its life,
The motor was run without the gasket between the head and the cam cover,
Or something else?

Suggestions appreciated
Thanks
Mark

 

[Charlie G]

I'm not certian what I'm looking at. Is this the valve cover?

cg

 

[Englishman]

I'm not certian what I'm looking at. Is this the valve cover?

cg

Yes sir. The inside of the valve or cam cover.

 

[Charlie G]

http://www.thegsresources.com/_forum/showthread.php?t=159474&highlight=lost+nut

If your bike is in running condition at this point, I would suspect that it has jumped time at some point. Meaning the cam chain became loose and jumped a tooth or more. In the above thread my tensioner failed, due to a nut comming off the unit. I resecured the nut, adjusted the tensioner and checked for damage. I was lucky, in that the valves didn't functionally damage the pistons and I was able to reset the timing and ride another day. Read over my thread and see what I had to do. Check the chain timing, check that the tensioner is set properly and do a compression check. I have read many times that when people aquire these bike that they find the tensioner has been improperly set. The proceedure is in the manual. It's easy, but often misunderstood.

I have a soft spot for those 400s, as my first bike was one. I value them greater than my 450, as they have roller bearings in them. Double check that your not missing a nylon cam chain guide.

My humble 2 cents. Cheers.

cg

 

[Englishman]

Thanks for the input Charlie. I'll do some checks as suggested over this weekend.

Mark

 

[Englishman]

Good news is that the cam chain has not jumped the sprockets. At some point in it's life the cam chain tensioner screw was not released to put tension on the chain. Looks like a lucky break.
Thanks for the help Charlie.
Mark

 

[Charlie G]

Good news is that the cam chain has not jumped the sprockets. At some point in it's life the cam chain tensioner screw was not released to put tension on the chain. Looks like a lucky break.
Thanks for the help Charlie.
Mark

I had found that on my 650, the PO had not lossened the set screw, to alow movement of the tensioner plunger. It was aginst the chain, but could not increase tension. I read in a post once that Steve made, that he has run into this numerious times on reserrected bikes. Cheers.

cg