Rear Cam Chain Guide Broke in Half - How to Remove?

[DaveP]

Just pulled off the head of my 81 GS650L and found that the cam chain guide has broken in half.



Doe the engine need to be torn down further to get this piece out and replaced?

 

[chuck hahn]

Gotta pull the jugs so it can be taken out. Now is a good time to put in new valve stem seals and clean the carbon off the valves and the piston tops. Do a basics top end refresh and youll be done for a very very long time. Depending on miles you can even consider honing the cylinders and installing new rings too. May not be a needed thing but its pen now is how i look at it if it was mine.

 

[chuck hahn]

This manual should do the trick.
http://zeus.mtsac.edu/~cliff/storage/gs/GS650GManual.pdf

 

[tom203]

I'm not sure how it's held in down there (and I hope never to have to find out!) but it has a hinge pin thru guide at bottom anchored somehow

 

[chuck hahn]

There are detents milled in that trap the lower hinge. If i remember right you start the jugs down on the studs then insert the guide into the lower detent from down the chain tunnel. then you finish setting the jugs down and this traps the guide.

 

[TeamDar]

You have to split the cases to replace the guide. The lower hinge is trapped in a groove between the case halves. Dar

 

[chuck hahn]

I stand corrected...page 3-19 shows removal after cracking the cases.

 

[DaveP]

Sounds like I have some more work to do. Will keep digging down and see what I find, but the manual definitely shows splitting the case to remove this guide and dampers.

 

[Guest]

Bummer.........what symptoms did you have that made you take the head off?

 

[DaveP]

I suspected the no. 3 intake valve was bent due to the timing jump and significant loss of compression in that cylinder. The number 3 intake valve clearance changed from 0.1mm to 0.24mm after the timing jumped suggesting that the valve was no longer fully seating. Visually, I can't see that in the valves with the head removed, so will need to do some more measurements once that valves are removed. Was surprised to see this guide broken in half, but it seems that it does happen.