Back story: I recently purchased a 1978 KZ1000 that has been sitting for around 4 years.
Here's what has been done this far:
Degreased engine externals- no real oil leaks but years of nasty.
PB Blaster into plug holes. Hoping this could loosen the rings IF they are stiff or stuck.
Oil change - old stuff was very spent but no metal that I could see.
Wired George has the carbs.
Static compression check is giving me about 30 psi on each cylinder even after several compression strokes.
I do have a cheap gauge that could suck.
Checked valve clearances. 6 are out of spec with too much gap and 2 are barely in spec. See chart below.
Will these specs cause that low of compression? Plan is to attempt to run the engine AS IS when refurbed carbs arrive. IF it does run I will redo compression check.
If it doesn't run should I get the valves in spec and go from there? IF I have to tear the top end down I will want some "hotter" cams so shims now will be a waste since the new cam will want what it wants.
Note: each valve has 2 clearance values indicating the thickest that goes in and next size up that doesn't. I have a basic set of feeler gauges so the formula averages these 2 numbers for further calculations to determine desired shim thickness for .080mm clearance.
I'd do the shims now. At least on the valves with tight clearance. And did you follow the cam position procedure detailed in the factory manual or did you simply point the cam lobe away from the valve when checking the clearance? If you did the later the clearances will show more clearance than in actuality due to skewing the cam in the journal clearance.
I posted earlier but it appears to have disappeared into the bit bucket.
Where do you get 0.08 as the spec? I don't have my book in front of me but from memory it's 0.05 to 0.15. The clearance is measured by the thickest gauge you can fit under the cam lobe. There should be no averaging necessary and you should be aiming for 0.15 because the gap decreases over time. You have five valves in spec and three on the high side, but not unduly so. I would leave them alone for now and concentrate on running the engine before you set valve clearance.
Your compression seems low but what's important is to have nearly the same (+- 15 psi between high and low) compression across the cylinders. Perform the test with all plugs out and the throttle wide open. Crank the engine until you see the greatest reading on the gauge. Normally it should be done with a warm engine, so don't put too much stock in readings on a cold test except to know you have compression.
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
Thanks for your reply.
I figured I over complicated that.
The .08 was since people are saying .05-.1 mm was ok.
Carbs are in a different State so no need to block them open they aren’t on the engine.
Check valve is there.
Plugs removed
Ran starter at least 50 revs for at least 5 compressions.
All cylinders around 35-40 psi.
When carbs arrive I’ll see if it runs and retest.
Sounds like we agree about leave valves along for now.
I'd put about two table spoons of oil in all cylinder's let it sit over night and retest comp.
1980 KZ650 F1
ZX750A1 motor.
Wiseco 810cc kit.
Zukiworks racing ported head.
VM 29 smooth bore's.
Dyna 2000 Ign. w/Dyna mini coil's
APE cylinder stud's and nut's.
APE valve spring's.
APE Track King clutch.
V/H KZ1000 sidewinder.
3.5x18 laced to a KZ1000 disk hub.
150/60/18 Shinko 006 Podium.
63" wheel base.
I think at this point I’m gonna wait for the carbs and attempt to run it. Luckily I’m out of town till next week so it won’t drive me nuts wanting to fix it.
Most of my suspension stuff has arrived but someone decided they liked my wheels too much and stole them
Kawasaki Shop manual indicates 0.05-0.10 mm. I agree with everyone that leaving it alone will be fine for now. I may be pulling the head to check the bores. It sat so long Im sure there was rust and pitting. My CL350 was really bad at the bottom of the stroke.