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Discussion Starter #1
Anyone know much about GS1100's? A buddy of ours called me to come over and check out the damage on his 82.

I don't usually do 4's so it was great opportunity to check this one out. Need to keep learning..

The right inlet cam cap was cracked into two pieces and the inner right was loose. The left inlet end cap also had metal smearing and that right end was destroyed.

Is that a common problem or did a PO not tighten the end caps properly?

I checked compression and it was 195-190-175-190. FSM says 160-171 IIRC. Very little carbon in the heads or on pistons. Is that normal?

All rocker arms were worn in a strange way ie they were indented at the valve side of the curved rubbing surface.

The complete head will be replaced with cams and rockers and we have a lead on a couple in WI, but is this "normal" on these motors or is there something grossly wrong with say the oiling system. Or was it just put together by a PO with loose clearances and beat itself to death?
 

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No, it's not normal. Can't tell you for sure what happened, but sounds like it was neglected and perhaps assembled poorly. Prolly a few reasons it failed as it did.
When maintained, even half assed, the GS mills are pretty bullet proof.
 

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GS or GSX? (2 valve or 4 valve motor?)
(makes a difference, roller bearing crank will survive stuff that destroys later plain bearing crank)
Cracked cam caps usually from bad servicing or a bad re-build.
Smeared bearing surfaces from blocked oil way (goes with the cheap re-build, probably find silicon in the oil pump pick up)
Check clutch cover look for silicon instead of new gasket, probably exploded a clutch and never cleaned out the 'plates' from sump
 

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It would be a 4 valve PJ as Teazer's mentioned rocker arms (the 2 valve heads were shim over bucket).

I've seen quite a few GS's (4 and 2 valve) have noisy top ends and excessive (lateral) cam float. My 1135EF was pretty noisy in the top end, but I can't say Ive seen cam caps disintegrate due to excessive cam float.

Are the caps in question threaded on top to accept the valve cover bolts? That might be a probable cause if some ham-fist has tried to overtighten the valve cover bolts (although I think that's only on the later EF 1135 mills....and the cam cover bolts normally just stip the threads before thay do any damage to the cam cap).
 

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Discussion Starter #5
Thanks for the input. It's a 16 valve motor and no screws in the tops of the cam caps. When we removed the exhaust cam, all the bolts were really tight and cracked loose. None of the intake cap bolts were very tight.

My suspicion was that the intake cam was swapped out or the PO started to strip the top end and gave up after loosening some of the cam cap bolts. Over time the cam hammered the caps and the end one broke. Smearing I suspect was caused by lack of oil on the inlet side.

My limited experience with the big GS motors was that they were pretty much bulletproof and are still drag raced, so I was surprised to see this mess. I was kind of hoping that someone would pipe in and say that the mode of failure was well known in motors where, X Y and Z were done. Sounds like this one is down a bone headed PO and a new owner who should have given it a complete service before he rode it.
 

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More likely someone was going to take cams out to adjust valves (trust me, seen it happen, common sense, isn't common)
If you don't tighten caps so they pull down even, they catch on the dowels and often crack (same if you take them off one at a time starting at the end)
You have 2 bolt or 4 bolt caps?
I've got a bunch of old Suzuki cam caps,(forget what they are off all together) I'll dig them out and check what I have
you can have them for postage costs if they will work
You'll have to check and adjust clearances as they were originally machined in position so matched to head
 

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Discussion Starter #7
Each cam has two outer two bolt caps and two inner 4 bolt caps. This one needs all 4 for the intake cam.
 

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Discussion Starter #8
Each cam has two outer two bolt caps and two inner 4 bolt caps. This one needs all 4 for the intake cam.
 

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Like PJ said, the cam tunnels and caps are line bored in place, so (theoretically) you need to replace the head with the matching caps. That's why they are always numbered and you shouldn't mix them up.

But getting replacement caps will obviously be better than what you currently have, so if you can find ones with acceptable clearance then it should be OK.
 

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Like PJ said, the cam tunnels and caps are line bored in place, so (theoretically) you need to replace the head with the matching caps. That's why they are always numbered and you shouldn't mix them up.

But getting replacement caps will obviously be better than what you currently have, so if you can find ones with acceptable clearance then it should be OK.
 

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I'll check tomorrow, Suzuki use a pretty 'standard' cam journal size.
I know I have a bag full, picked them up a few weeks ago looking for something else (just have to remember where I put them down ;))
 

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I'll check tomorrow, Suzuki use a pretty 'standard' cam journal size.
I know I have a bag full, picked them up a few weeks ago looking for something else (just have to remember where I put them down ;))
 
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