79 GS1000 cam mark/score

[Guest]

I have just started removing the top end as part of my 79 GS1000 project and after removing the camshaft cover I found scoring on one cam. Any thoughts on what I should do, it does not seem deep in fact I do not even feel a groove.

[HaggisHombre]

Also as I will have to do the shims on rebuild, is this the time to do them before I pull it all apart?

[GregT]

Without seeing the rest of the cam lobe I'd guess that there may be something imbedded in the shim which has made that mark. If you can't feel any groove - the fingernail is very sensitive - i wouldn't worry. You're probably going to have to change the shim after lapping valves anyway...

Which is the reason you'll reshim after reassembly of the head - but you can do it on the bench rather than in the bike.

[HaggisHombre]

I will double check using the fingernail test this evening. I am glad to hear this, it does make sense. Thank you.

[chuck hahn]

That or the tip of a pin...How does the top of the lobe look???

[sharpy]

Why isnt there ANY oil sitting around. There is none any where, i know its next to the cam chain tunnel and it drain when leant over but none on top of bolts or anywhere

[chuck hahn]

Maybe he wiped it off before snapping pictures????? I would have anyway.

[HaggisHombre]

I have not had a chance to turn the engine to see the top of the lobe. I bought the bike about two years ago. I drove it home and it has not ran since , I have not even turned it over. Perhaps that is why there is no oil on the bolts etc. There is oil under the cam lobes. I appreciate the input.

[HaggisHombre]

Here is the pics.

[GregT]

Well, well, a hole in the center of the shim....never seen that before.

I wonder if it's a home made shim - or if someone saw fit to put a center hole in it to grind it.

When you pull it out, if it's still got a marking on it, check it is the stated thickness, just out of curiousity.

[koolaid_kid]

I suspect the hole is what made the mark. I'd chuck it.

[Nessism]

Nice thing about the shim and bucket GS engines is the valve train is so stable. There is a lot of cam surface area to take the load so that little score line won't matter at all. I'd ditch the shim but keep the cam, assuming the journals are within the service limit.

[jsandidge]

same thing

I did a shim swap with a local dealer a couple months ago. The only 2.50 they had bore the same mark right in the center. Looked like someone used a center punch on it. The mark was on both sides. You could feel it with your fingernail. I was afraid of what it might do to my cam. I said thanks, but I won't be putting that in my bike! Bought a good one from Z1 before joining our shim club.