Valve Cover Removed - what's going on here?

[Guest]

Hi all! I am diving in to my first project with a 1982 GS750E (last time it was run was in 1987), where we are using this opportunity to learn as much as possible about bike maintenance, performance, etc. As such, there are certain things i have no clue about - this being one of them. Why would the exhaust cam show so much wear but the intake cam appears flawless? What are my next logical steps here?

[eil]

If the cam surfaces are smooth, you have nothing to worry about. It's not wear--they all look like that after some miles.

The reason the two look different is because your engine appears to have solid followers on the intake side and split followers on the exhaust side. Usually it's one or the other, I don't think I've seen both in the same engine.

[a3tripod]

That's reassuring! I do see now that one side is split and the other is solid - thanks for pointing that out. From an inspection standpoint - checking tolerances, etc., do you recommend i do more than check tappet clearance?

[posplayr]

WHOOPS I see Eli answered this:

What you are looking at is a difference in follower designs between intake and exhaust. The exhaust followers are split and so they do not scrub the engine gunk from the cam down the middle. The intake has a full follower (like the GS1100E have on both IN/EX). So you are not necessarily looking at increased wear on the exhaust. You would need a caliper to measure the lope height to determine that.

The lob heights can be compared to the factory spec but you might need to consider what the rocker ratio is which I think for the GS1100E is 1.5:1 (lift vs lobe height).

BTW, the exhaust cam is the identical part number to the GS1100E 80-82 cams although the cam gear is different.

[a3tripod]

Ok - so I'm a little lost on how to determine the came lobe ratio. Where exactly am I measuring from:to?
In terms of my valves - i just got back in from checking and they all seem to be within range of the specification .08-.13mm. Actually they were all nearly the same, right at .10mm.

[Nessism]

That engine you have is the least reliable in the GS family. Camshaft and rocker wear is quite common, as are rod and main bearing failures. Those cams look pretty good but regardless, you may want to consider shimming the oil pressure relief spring (in the sump) to hedge your bet. From what I understand you need to add a washer or two that totals 1.5mm thickness to increase preload. This was a factory recommend fix although I'm not sure it was ever documented in a TSB. Another thing to do is make sure you use a high ZDDP oil. A lot of forum members use Shell Rotella diesel engine oil, but there are other good choices as well. Brad Penn oil is high ZDDP and would be a good choice too. Main thing is to stay away from automotive oil.

[a3tripod]

I keep plenty of Rotella on hand, as I have an F350 diesel, so not a problem there. I haven't inspected the oil pump or sump yet, but that sounds like solid advice -Thanks! With regard to camshaft and rocker wear - i'm not sure how to measure that?