1981 GS750E Cam condition question

[woodsietx]

I adjusted the valves on my GS last weekend and had the thought this morning that I might want some opinions on what to look for to determine if the mechanicals at the top of the engine look ok. The bike did not seem to exhibit any symptoms of bad valve adjustment before it stopped running. Those who have followed my saga may remember that the carbs are the most likely suspects for my issues. I did the valves because of advice here that a carb synch is best with properly adjusted valves.

I have some pictures of the cams below. I noticed that the exhaust cams have a definite difference in color. They show two "grooves" on each lobe. As I recall, there is no groove in the metal, just a difference in color. Is that normal? The gap in almost every tappet was a bit loose. The .005 gauge went under with no resistance.

I have not fastened the cover back on the bike yet. I'm waiting for stainless bolts. I hope to finish that over the long weekend. Before I do, however, I can re-examine the motor if I know what to look for.

Anything that can be suggested would be appreciated. If better pictures are needed, I'll be glad to take more. Who ever thought a camera would be a valuable mechanic's tool??

#3 & 4


#1 & 2

[rapidray]

Looks fine to me! Adjust the valves to the factory specs, put a dab of "anti-seize" on the threads of each of your new stainless bolts, & put it back together. Re-sync the carbs & go from there! Ray.

[Nessism]

Those are the engines that eat their cams/rocker/head. Is there anything that can be done to get more oil to the cams and avoid starvation?

[rapidray]

A top end oiler like we use on the 16 valve GS drag motors & big street motors will help. Actually, they are more notorious for eating rod & main bearings than the head parts. Ray.

[Nessism]

One guy here that claimed to have worked at a dealership back in the day, said that they used to shim the pressure relief spring to increase oil pressure. I think I'd look into that further if running one of those engines.

[rapidray]

I have done that too but it CAN cause issues with the oil filter. We had filters come apart a couple of times because of the pressure. Ray.

[Larry D]

After mine puked I looked around for a top-end oiling kit. Where could someone purchase one for an 80-82 750 ?

[rapidray]

Larry, GregB on here is a machinist & is making some & has parts in stock. Send him a PM. Ray.

[Larry D]

Larry, GregB on here is a machinist & is making some & has parts in stock. Send him a PM. Ray.

Thanks Ray.

[woodsietx]

How does a top-end oiler work and what do you have to do to the engine to install it?

[rapidray]

It pulls oil from under the cam chain tensioner, where the pressure sending unit is, & sends it straight to the cams for extra oil to the cams & rockers. Ray.

[Ricko19]

Hi Woodsie,

I'm at the same place as you at the moment and was wondering the same things - cover is off but haven't done the valve adjustments yet.

I too was wondering if the grooves on the cam were ok (discolouration) but seems ok now

Still cleaning the old gasket crap off the sealing surfaces, then will do valve clearances. Then when I get my nice clean carbs back from Zooks I'll be ready to roll again.

Haven't ridden it for a few moths now and am getting withdrawls! It sucks only having one bike!

[woodsietx]

Amen brother, I feel your pain.

I only hope my electrical system is OK or it means even more down time. I can't afford to replace batteries, R/R and stators more than once.

[gearhead13]

A top-end oiler on these engines would be hard to install because there is no pressure sender unit under the cam chain tensioner like the 1100's. It would have to be plumbed a different way. When I redid my 750, there were restrictors in the oil passages leading up to the head, maybe they could be opened up a little?
AS for shimming the oil pressure relief valve I seriously thought of doing that when I had mine apart. I just didnt have a clue as to how much to shim it. Any ideas? Ray?

[rapidray]

I would start with no MORE than a .040 shim. Ray.