First time GPz1100 valve clearance-timing work. Could use some voice of experience...
- Duck
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Couldn't wait to see what I got so took day off from home renovations and made a trip to the shop...
PO said he was getting backfire through throttle bodies.
He said, 'Compression was 50-60 on all so I measured the shims clearance and intakes had none but all exhaust were OK.' So far so good.
He said, 'I took one shim out and compression on that cylinder read 180'. OK, so good chance the associated valve isn't burned.
Then he said, 'I moved the Intake cam one tooth'. Huh???
Well I got the valve cover off and sure enough, the intake cam is advanced by one tooth. Rational escapes me.
Here is where things start to go weird, for a guy who has never had one of these apart before.
As I turn her over, the chain seems to sag down between the two cam sprockets and then pop up. Turning clockwise as per manual (unless Japanese clocks run backwards, mugbus anyone?).
I'm thinking, hmmm.... tensioner may not adjusted, Could it be?
Another weirdness is the force required to turn the crank over is not uniform, even though I have all the plugs out. It's not difficult to turn, just easier in some parts of range and a bit tighter each time the cam chain sags.
Anyone have a clue as to what I'm looking at here? Hopefully nothing that's case cracking serious.
I'm going to finish this cup of coffee and go back and set TDC and put the chain on the right correct tooth. Want to check, just in case he moved exhaust instead of intake.
Once that's done, I'll check the clearances and make a run over to the bike shop to see if they have any shims.
Have a quick question re grinding shims if bike shop is lacking an assortment. The manual says do not grind because they might crack. The guy I rent from has a 24" surface grinder with the right wheel in it. He sharpens dog food making machine knives... Should I heed the manual on this or is it OK to grind valve shims?
Advice regarding any caveats for first timer working in thiis area will be appreciated.
I've only got today to work, then I have to work on house until Sat or Sun. Gotta get new bathroom finished.
Thanks,
-Duck...
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- Fendrguy
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I wouldnt grind those shims, there only 5 bucks a peaice. since you have to wait on the bike to get the bathroom finished, ya might as well wait for the right shims to come in if you need to order them.
I just bought some for my 650 a while back and found a dealer that does trade ins. he charged me 2.50 a shim. you might want to check out if your local does the same.
best of luck on your bike.
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- wiredgeorge
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Soooooo... first correct cam chain issues, then set valve lash and repeat compression check. Don't worry about backfiring as I would expect a bike with this many small issues to backfire. If you get the cam chain sorted out and the valve lash set, and compression is good, then start the bike and most likely ride away...
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- RonKZ650
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321,000 miles on KZ's that I can remember. Not going to see any more.
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- craigpuckett
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Doesn't the GPZ1100 use the hyvo cam chain with the center tensioner mounted to the valve cover? It's been a long time since I owned a GPZ1100, but if this is the case then yes there will be play in the chain between the cams and yes the engine will jerk forward on the intake cam in certain points of rotation. Try pushing down on the chain between the cams as you turn the engine to kind of simulate what the tensioner would be doing after the cover is installed and see how it feels then.
Ron hit the nail on the head,hi-vo camchain with center tensioner will always do that,also when you replace the valvecover on a hi-vo type chain you have to reset the auto chain tensioner or you will stretch the chain or wear out the chain guide slides.
the hi-vo chains are around 95.00 and you have to split the cases to replace them.
P.S. good score,I wish it were mine.the first thing that would go is the efi. if you do change to carbs you will also need some J1000 sprockets for the cams.
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- wiredgeorge
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- RonKZ650
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wiredgeorge wrote:
Ron, I think the cam chain tensioner is at the rear of the engine the same as the older KZs. It is an automatic type if memory serves but I am not really positive. I recall it has a pushrod/spring but there is another smaller springloaded rod on the side that governs how much the bigger pushrod moves outward against the rear cam chain guide (piece that puts pressure on the chain to tension it).
321,000 miles on KZ's that I can remember. Not going to see any more.
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- Doebag UK
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Ride safe Doebag
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- Duck
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Yep, Hy-Vo
Yep, guide ,material in top of cam cover. BTW, how much wear on this guide would there have ot be to suspect all the guides. It's clearly scrubbed but is not grooved a bit. When I drag a fingernail across it(lect to right engine sides) there is no noticable change of depth and no ridges. Clock shows 23k miles but title says miles are incorrect.
The manual says it's a non return type tensioner. However, I can push the tension rod in by hand. Have not read manual section on tensioner disassembly. Have to wait until the weekend for more time to work on this. Unless by some sort of intervention form the gods, the bathromm prokect completes sooner than expected
.
One of the cam caps on the exhaust side was found to be missing a hollow guide pin. I phoned the PO and he thinks it's on his work bench.
Asked him to measure ID, OD, and length and email to me for comparison. Hopefully it's on his bench and not in the engine.
I may pull the oil pan anyway because he does not know where the one missing intake shim is
First he said he took it out to measure compression because there was no clearance. Now he says the bike came to him without it. He never had the bike running so who knows.
One of the exhaust cam caps had a heli-coiled bolt. No big deal, all the others are nice and clean.
Wonder if anyone here ever owned this bike. It lived in Arkansass, moved to Alabamistan but never ran there, and now resides in the peach state.
82 GPz with average to good black repaint on bodywork and poor black repaint on engine. Really nasty dented up kerker head pipes and megaphone without baffle. Suspect they went on the bike in their present condition because they are way nastier than the rest of it.
It is all there. Airbox, snorkles, throttle bodies, and holders in good shape. Huge battery in this thing.
Thanks for help guys. Will post more if progress or questions this weekend.
-Duck
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- wiredgeorge
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- Mcdroid
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Michael
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1982 GPz750
1977 KZ1000A
1978 KZ1000A
1982 GPz1100
1975 Z2A
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- wiredgeorge
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