1980 KZ750 E Cold pipe, no compression, opening valve cover

Possible collision with the piston? Intake side, pic 2 is zoo.ed in, faint ( shape...

Nailed it, thanks!  The intake valve was bent.  It passed a water leakdown test, but it was really stuck in the valve body.  New valve and seat NOS and OEM shims ordered. Thanks eBay sellers vintagekawchick2015 and D's Cycle Connection. 

My local Kaw shop wanted me to drive over and pay before they ordered parts they should have.

howardhb post=903203 userid=56325That clearance of 0.43mm would seem to indicate that the valve is either bent, or, something is stuck in between the head of the valve and it's seat, preventing it from closing.
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The cylinder head will have to come off I'm afraid...

H.

Woah, just saw your reply!  Frack!  I found the intake valve bent visibly. 

Cam chain checked, not replaced. You noticed a difference in a new chain?  I think all sprockets must be replaced as well or it stretches the new chain to match the gear slack from worn teeth (per bicycle drivetrain consumables).. 

Think I upgraded stock to a better auto tensioner.  Someone used to make a manual tensioner replacement or there was a mod...  here on Z1:

www.z1enterprises.com/cam-chain-tensione...0-1000-77-80-z1.html

Injected wrote:

This looks like the same thing that happened to me on my '82 KZ750 top end rebuild.

The main culprit was a malfunctioning cam chain tensioner, that big ugly double wedge job. I bent two valves because the cam chain had slop in it when first fired. No compression in one cylinder, one intake valve bent .002" and one exhaust valve bent .004" both straightened on lathe then reground.

Did you replace the cam chain with a new one?
If you don't then the cams will never line up at TDC like the manual shows, always up or down from the gasket surface. I ended up setting my cams up by using a dial indicator on the tappet to tell me when the valves were closed! I have since ditched the giant auto tensioner for a manual unit.

This spring I am going to slot my cam sprockets so I can better set the cams up, this is one way around a slightly elongated chain (the chain was within FSM limits)