shim size all over the place.....

[Guest]

1982 gs1100 gk.

hadn't run for the first year i owned it while i was going through it.

I checked all the valve clearances and it seemed like some were a little tight - like i was swapping 2.50's for 2.45's or whatever.

Finally had it running for maybe 20 total minutes off and on until i jammed up the effing cam chain.

Finally got that all sorted out but when i had the valve cover off I thought i'd recheck my clearances. Now I did have the cam out while I jacked with the chain, but then tightened it all back down to torque specs.

So SOME of my clearances were still good (mostly on the exhaust side), and ONE on the intake side was fine, but THREE were like WAY OFF. I swapped two 2.50's for like two 2.90s (and the clearance is back to 0.03 mm, so I'm happy with that), but my other one I swapped a 2.50 for a 2.95 and it's still like 0.17 mm open.

Doesn't that seem weird? Why would they all be so far off all of a sudden? Something get loosened up after I put 20 minutes of RPM's through it?

It turns over (by hand) just fine now. Haven't put the battery back in yet.

Any thoughts?

[dorkburger]

Not sure what jamming up the cam chain means, but im guessing it was loose? Tensioner problem?
Hopefully its not bent valves......

[Chopperjake]

tensioner was bad. chain was loose. engine got locked up while trying to turn it over. but that's all fixed now. new tensioner. chain is tight. turns over fine.

[Steve]

Was the engine running when the chain "jammed"?

If it was, I would put my money on bent valves.

.

[Chopperjake]

Actually no. I hit the starter and it went "thunk". I haven't taken the top end off, but it turns over fine now and it's clear that the "thunk" was from the loose cam chain. (see my other thread for that fiasco....)

[Nessism]

You bent those valves. Sorry.

[Steve]

It may not have be 'running' on gas, but being powered by the starter motor is close enough.

There was sufficient inertia involved. Time to look for a replacement head.

.

[Nessism]

I'd pull the head and check it out. You may just need a couple replacement valves.

[Steve]

I'd pull the head and check it out. You may just need a couple replacement valves.

Any valve that suddenly had "extra" clearance will need to be replaced.

If you want to get new valves, Parts Outlaw has intakes for $32.47, exhausts for $54.43.

.

[Chopperjake]

I know you guys are probably right, but you know how you try to doubt the facts when you really don't WANT it to be right?

It seems unlikely that I would bend 3 valves all on the exhaust side and nowhere else, doesn't it?

I was thinking maybe since my #1 intake clearance was good, but my #3 and #4 intake were wide open that maybe I tightened down the cam too much on the left side of the bike and so the right side of the cam didn't get pulled down as far, even though I torqued it to spec. (I know the bolts were way over-tightened when I took it off).

I was thinking about trying to loosen and re-tighten the cam more evenly to see if it evens out.

Plus when my cam chain gave me issues I thought about taking off the head and was going to, BUT THOSE BOLTS WERE TIGHT!!!!!

And I really don't want to be breaking off bolts, because I broke off 3 the first time I took off the valve cover and then I was so mad that I didn't touch the bike for a year....

1. Any chance if I re-tighten my cam that the clearances will improve?
2. Can I just try compression test with the starter to see if it's good and then not pull my head?

thanks for all the input.

[Nessism]

By all means, try a compression test.

The only way the cam bearing caps could be causing a problem is if the caps are not seated on the head.

[chuck hahn]

The extra clearnce was from the pans being bent and thus drawing he stems further down. The guys are right dude...bent valves.

[Chopperjake]

damn......

Ok, I'm warming up to the crappy idea of pulling the head. (I'm not intimidated by the idea of replacing valves, just nervous about snapping off a stud).

Chuck, I'm not sure what you meant by "pans" being bent. Is it in this diagram?



Any good ideas on how to get off 40 year-old bolts?

[chuck hahn]

The valve itself..we used to call them PANS way back when. They looked like the bottom of a pan from the bottom. The stems bend and they dont seat again..thus they make the clearances all jacked up. The compression check will show that in an instant.

[Chopperjake]

Just a little follow up........you guys were right. There, I said it.

In the interest of science I went ahead and did a compression test - my #1 is like 150 (that's the one that didn't need shim changed), #2,3,4 all basically a big, fat ZERO!!!!

So here I go, pulling the head off.......any advice? I'm soaking with PB now. Does it matter what order I remove in (because they tell you to tighten them in a criss-cross pattern from inside to out). Any other tips for not snapping **** off?

thanks for all the help. ****ed that I took a bike with good compression (I had checked before) and got running (YAY!) and now F'd it all up because the damn cam chain tensioner was bad.