KZ750H Valve Lash Decreased AFTER Clearance Job? Can of worms.

Hoping for some insight or help here before I go tearing the head off/replacing it.
I've got a project KZ750H that I recently got running. Bike sat for 20+ years in a PNW shed.
I've been going through the scheduled maintenance items and recently did the valve clearances. However I've run into a problem.

Problem:
#1 Intake has progressively louder valve ticking after riding the bike (usually less than 20 miles, and no faster than 60mph). The increase in volume is VERY noticeable. That is, when I start the bike it sounds like normal valvetrain noise and after it's warm it is a very prominent and loud valve tick.

I pulled the valve cover/cams again to triple check my clearances and come to find out #1 has a smaller clearance than before replacing its shim.
Before replacement: .1mm with 2.40mm shim
Replacement: 2.35mm shim to bring to ~.15mm
Current: ~.04mm
I measured the replacement shim just to ensure it wasn't a fluke and it's on at 2.35mm (as far as my chinesium calipers can tell)

Compression measurements (the second measurement follows the manuals "add a teaspoon of oil":
#1 100psi
w/oil 125psi
#2 125psi
w/oil 165psi
#3 95psi
w/oil 125psi
#4 105psi
w/oil 130psi

My current thinking is:
The shim bucket is sticking after getting warm. (It was a little tight pulling it with a magnet but nothing that stood out as faulty)
Piston rings need replaced (which is just realized after pulling compression... UGH)
Bent valve/guide?
I talked with a wise KZ sage about the issue and he mentioned some known issues with updated valves on J series engines being brittle.
I am working on borrowing an endoscope to confirm/deny this but want to rule out the easy stuff first.

Any and all help is appreciated!


 

Quite a few things can make a ticking noise, and it is notoriously difficult to tell where one is coming from. A small exhaust leak at the head can tick. A valve with too little clearance is unlikely to make any noise. As long as the bucket moves smoothly in the bore, there should be no problem. If the valve was bent, there would be a gigantic clearance as the valve could not fully close. I would try a thinner shim and see what happens.

Are you measuring the compression while the engine is at operating temperature and the throttle fully open? If not, you will get unreliable numbers. A leak down test is far more informative than adding oil to a compression test. If you have a compressor, you can do a poor man's test by putting pressure in each cylinder and listening for air escaping from the exhaust or the carbs.

Your bike does not have  J engine. They came in 998 and 1089 cc versions only.

Thanks for the help! That is at least partially comforting. I was beginning the grieving process of tearing the engine down...
I'll try an air pressure leakdown test. Assuming just get as best of a seal as possible in the spark plug hole?

Replacement shim is on the way. After install I'll post any updates.
Any recommendation for things to check while the cams/valve cover are off?

Also, any special tips for cam lube placement? I bought some Torco Assembly lube to drop in the shim buckets (as a precaution)

Thanks again!

It would be best if you had an adaptor for your air hose that would thread into the spark plug hole. A cheaper alternative would be a tapered rubber plug that fit the spark plug hole tightly. You would need to drill a hole in it so that your hose nozzle fit really snug in it. If air is leaking at the plug hole, you may not be able to hear it escaping other places. Be aware that if you use a lot of pressure, it will push the piston down. It would be good to avoid that if the cam cover is off.
No special lube is needed for this. A little engine oil is fine, but the lube will not hurt anything. If it gives you peace of mind, use it.

Heading out to do a leak down now. The compression tester I have has a threaded adapter luckily.
Plan to replace exhaust gaskets today as well just to rule that out.

Bought shims from Z1 to replace Intake #1. Before starting the job I took a feeler to it and now it's in spec but exhaust #1 isnt???
Am I taking crazy pills?

These gaps should be relatively consistent right??

 

Perfectly consistent.
Are you following the measuring procedure in the fsm?

If the valve clearance maintenance has been neglected and the clearance has reduced to nothing the valves will hang open and not close all the way when the engine expands and is hot.  When this happens carbon begins to build up on the valve and seat contact surfaces, and if further neglected the valves themselves can burn and even crack/fail.  Assuming the valves are not damaged and just have some carbon on them, it will take some miles after adjusting before the carbon is burned off the sealing surfaces.  In other words, your newly adjusted valves may further reduce in clearance until all the carbon is gone.  Anytime you find no clearance or a very small clearance when cold, and you adjust the valves to correct this, it's strongly advised to double check the valve clearance after a few hundred miles to make sure the clearances have settled in properly.

Hi. I had a similar problem with a 650 some years back. I couldn’t get some of the clearances to stay right. Every time I turned the engine over to double check them they’d changed. Turned out to be worn cam journals allowing the cam to move up and down slightly. You can check them with a plastigauge kit. Hopefully it’s not that and as Nessism said it’s just carbon buildup!

Thanks all for the replies.

So I did a leakdown test. Couldn't hear anything escaping.

Went ahead and replaced two more shims to bring them into spec. Just turned the bike over and the ticking is worse.

I think I may have figured out part of it though. Whenever I inspect the clearance on the suspect valve I get different measurements depending on where the lobe is pointed. 
If I point the lobe how the manual says, away from the bucket, I get too tight of a clearance which points to replacing the shim. IF though I take the measurement with the lob pointing just off in either direction I get the correct clearance. 
When it cools I plan to tear it down again (I am getting VERY good at this valve shim job....) and checking my theory as well as the cam lobe itself. 
Would there be any good hints? Discoloration or anything like that?

Also, any tips for diagnosing an exhaust tick? I think it's contributing to the noise slightly.

Hold on.
Are you checking the valve clearance when the cam is on the base circle for that particular valve?
The bucket has to be resting on the base circle of the cam when checking clearance.

 

wrote:

Thanks all for the replies.

So I did a leakdown test. Couldn't hear anything escaping.

Went ahead and replaced two more shims to bring them into spec. Just turned the bike over and the ticking is worse.

I think I may have figured out part of it though. Whenever I inspect the clearance on the suspect valve I get different measurements depending on where the lobe is pointed. 
If I point the lobe how the manual says, away from the bucket, I get too tight of a clearance which points to replacing the shim. IF though I take the measurement with the lob pointing just off in either direction I get the correct clearance. 
When it cools I plan to tear it down again (I am getting VERY good at this valve shim job....) and checking my theory as well as the cam lobe itself. 
Would there be any good hints? Discoloration or anything like that?

Also, any tips for diagnosing an exhaust tick? I think it's contributing to the noise slightly.

Kawasaki changed their cam positioning methodology over the years.  I prefer the method they adopted for the later year 1000/1100 engines, which incidentally happens to match the Suzuki GS method, which employs a very similar engine configuration.  With this method you position the cams such that valves are adjusted in adjacent pairs where both are on their base circle.  This method is simple and foolproof, and assures the adjacent valve isn't depressed and pushing up on the cam, skewing it in the journal clearance.  

The method as detailed in manuals like Clymers is just flat out wrong.  

Thanks Nessism. I had read a post of yours in the past talking about that. 
Does the base circle take up approximately 180 degrees of the lower portion of the cam? 

Going to go recheck today with your method.