engine poorly

well after rebuilding my 650 motor.
glaze busted the bores, proper valve job, mild port work, new coils etc etc
old rings gapped up ok, valve clearance all good i have little or no compresion on all 4 pots.
cam timing seems spot on, only thing i am not 100% sure on is the cam pullys. 95% sure there on the right way and im guessing if they were 180 out i would have valve piston clerance problems.
head is now off the engine and no sign of anything touching.
first thoughts are the rings are to worn and it needs new ones but at £250+ for a set i was thinking of a engine trensplant.
what fits? thinking along the lines of a zephyr 750 motor.
cheers rob

"have little or no compression on all 4 pots"...

@ 1/4 TDC (ignition timing cover 1/4 on T), cam lobe tips should be facing each other and parallel with the head deck. Is this correct on yours?

On KZ900/1000... Should like as in image on the top right.
Not sure about the KZ650 dimple marks so ignore in this image set for again, this is for a KZ900 but I would think the lobe tips should be the same...

Other KZ650 members should be able to confirm....

Never tried using old rings after honing and would not recommend it! Buy the rings if bore is still at correct size, also make sure off the ring land fit at the piston groove. Sounds like you unbolted the sprockets off of the cam's? The manual will show the proper installment of the sprocket to each cam as well as the proper timing for the cam's to crankshaft. Did the valve clearances get reset after the "proper valve job"?

Ok, found this in an Non OEM service manual... Maybe it will help, maybe not....

like i said i'm sure the cam sprokets are on correctly, they were removed as i had a pair of big cams when i rebuilt the engine but swapped them back to stock after i couldn't get it to start.
bores were not honed just a light glaze bust.
i have the same pages as posted about cam timing and have tried it at least 4 times by the book and it all comes out right.
checked all the valve clearances and they all came up in spec.
even had a degrea wheel on the crank and the cam timing is is to the book so im pretty sure that is correct
really baffeled by this one and its not as if i dont know engines as i build race engines for a living [aircooled vw motors]

Ah another VW man! I spent years on those motors.
So I know its hard to do without having the upper snubbing block in the valve cover holding tension on the chain, but you should have an equal split in valve over lap on TDC 360 crankshaft degrees off of compression stroke. This will tell you if the valve timing is on, look and see if the intake starts to move when turning in 1 direction and the exhaust in the other, equal amounts for the same number of degrees. And the valves should nearly close when on this TDC, all with #1 cylinder. When together you did a compression test, but did you do a leak down test or at least blow air into the cylinders to see where its escaping?

I think OMRs' got this one...
anywho:
judgie wrote:

swapped them back to stock after i couldn't get it to start.

So it runs now? That would mean that you have at least 100 pounds compression on 2+ cylinders...

bores were not honed just a light glaze bust.

Glaze bust or not, old bores are old bores... did you spec the pistons to the bores?

i build race engines for a living [aircooled vw motors]

OK. If your 100% cam timing etc is perfect...
The same priciples apply here. Compression requires the valves to be seated completely as the piston rises on the compression stroke.
Make sure headgasket is tight.
WOT, all plugs out - Do compression test - list numbers.
Pour 2 teaspoons oil into each cylinder, do another compression test - compare numbers.
Compression rises sharply with oil - bad rings and/or piston combo.
Compression stays nearly the same - Valve seating/cam timing issues.

GL bud!