Valve clearance check after a valve job

[rwcfrank]

Hey everyone, I tried a search but there were too many opinions to sift through and I need a short straight reply. I am having a valve job done on my 78 GS750 2 valve. Once it's back how do I determine the very first try at shim thickness. Is there a trick to it? Right now a few of the valves had just about zero lash.

[tkent02]

Put in a much smaller shim and measure the clearance, you can then figure out the correct size.

[7981GS]

Are they installing new valve seats?

Eric

[rwcfrank]

Not sure about the seats, I reckon if it needs new seats I will find a lower mileage head and have that ground. I took the head off today and the cylinders look incredible, I can still see the cross hatch. the valves dont look quite as good but I will know more after disassembly. This mind you is a bike with 80,000 and it was puffing just a little on the right side after 5 years of rest.

[tkent02]

I can still see the cross hatch. the valves dont look quite as good but I will know more after disassembly. This mind you is a bike with 80,000

That's how they roll, usually. 80,000 is not much for these engines.

and it was puffing just a little on the right side after 5 years of rest.

Probably a thousand miles of hard riding would have fixed the puffing.

Resting is not good.

[rwcfrank]

Okay then, here is the cheap in me coming out. I think I should change the cylinder base gasket to avoid leaks. Dare I ignore a ring job and just clean the ring grooves?

[tkent02]

Okay then, here is the cheap in me coming out. I think I should change the cylinder base gasket to avoid leaks. Dare I ignore a ring job and just clean the ring grooves?

What do the rings look like? How was the compression before you took it apart?
With all of the cross hatching still there, there can't be much wear, but on the other hand, rings are cheaper than doing it again next year, and breaking in new rings is fun Any excuse to haul ass is fun.

Yeah, hone the cylinders and replace the rings.