Valve Noise/No compression

I did a valve adjustment on my 1976 KZ900 a couple of days ago. Today I took the carbs off and cleaned them. I also did a bench sync on them. I put the bike back together and after starting it, I was able to turn the choke off after it was running for 30 to 45 seconds or so. I did notice a noise that I think is from the valves. I dont remember hearing it before doing the valve adjustment.
Here are the valve measurements:

#4 intake - 2.55 shim and .102 is the biggest gauge that will fit.
#4 exhuast - 2.30 shim, .152 largest that will fit.
#3 intake - 2.60 shim, .076 largest that will fit.
#3 exhaust - .152 largest that will fit, dont know what shim is installed.
#2 intake - 2.45 mm shim, .076 largest that will fit.
#2 exhaust - .127 largest that fits, dont know what shim is installed.
#1 intake - .102 largest that will fit, dont know what shim is installed.
#2 exhaust - .127 fits, dont know what shim is installed.

All of these are within specs I believe. Could the valve cover not being tight enough allow you to hear the valve noise. Is there a way to tell which valve the noise is coming from ?

As a start you should sync the carbs. The bench sync is only to get them in the ballpark, and that can be a big park. The goal of synchronizing the carbs is to set them so that they all have equal vacuum at idle. When you bench sync carbs you ensure that all the slides are at the same height, and in a perfect world, that should result in equal vacuum. However, the reality is that that are other factors that affect vacuum (condition and clearances of valves, condition of pistons, rings, etc.) so even if a perfect bench sync is performed, the vacuum from carb to carb may vary. This is why it is importance to synchronize the carbs with the engine idling. Doing that allows you to compensate for any minor differences between the cylinders that may affect the vacuum at idle. Ed

After cleaning the carbs and bench syncing them, I didn't have time to put the running sync. Hopefully I'll be able to do that this weekend. The cleaning and bench sync has it running good. I just need to do the running sync and found out about the valve noise.

I finally got back to this the other day. I started the bike and it sounded like a valve was tapping and it wasnt running on all 4 cyclinders. The #3 pipe was not getting as hot as the other 3 pipes. I checked the valves again and had hard time getting the shim out of the #3 exhaust bucket. I had to take a small screw driver to pluck it out. It seemed like the shim was stuck in the bucket. I put the largest shim that I have (2.70 mm) in and the .178 mm feller gauage will fit between the shim and the came lobe. I also noticed that there was lots of oil when the exhaust valves are. Is it normal for oil to be there ?

Oil is normal. Most valve noise is not valves, it's exhaust leaks up at the head to exhaust seals.

I may be mistaken, but wouldn't going up one shim size on both #3 & #4 exhaust bring those into the center of the adjustment range?

I am getting ready to check on the header now. Can the valve being too loose cause the #3 plug to not fire correctly ? If I have the bike idling and pull the #3 plug wire, the rpm' stay the same.

I ordered larger shims from Z1 last night. I am hoping that they will cure the problem that I am having #3 plug not firing like the other are.

Was lack of combustion in #3 cylinder an issue before the carb work?

Good Fortune!

When I did the shims, I also took the carbs off and cleaned/bench synced them, so I am not sure. The largest shim I have is 2.70 and I believe a .224 feeler gauage fits between the shim and the cam lobe. I should be getting my parts tomorrow.

I believe I've read on this board (might have been the kaw motorcycle board) that "a slappy valve is a happy valve" and I've followed this in practice by having some valves set at the top of range (.152) without issue. I've read that range given in the manual is conservative. To add to that, I thought hearing the valve clicks from the head after an adjustment when tolerances are loosened is a good thing. It's an indicator that the valves aren't tight. Someone correct me if I'm mistaken with all this.

BIGKEVIN wrote: Is there a way to tell which valve the noise is coming from ?

I use a stethoscope with the diaphragm at the end removed (so it's just the tube). This let's me position it in very specific locations to identify where noises are coming. I've found this to be a big help diagnosing certain issues. basically this but without the metal tube at the end:

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