Kz1000 valve clearance way too loose

I just swapped heads on a 78 1000 for a guy. Took his off with all the valves bent, can chain tensioner backed the whole way off, and replaced it with one of my spares from the piles. Put it all back together and went to check valves and clearance is up around .280 on 6 of them and the all have .260 or .255 shims in them. Am I missing something here? How looses is too loose? Long time no post but I sure could use the help guys. Thanks

.002-.004" / .10-.15mm. What do you read?
Steve

What does .280 mean?
Is that .28mm or a #280 shim?
If .28mm, that's 0.01" and a huge gap.
Otherwise your question seems to have syntax confusion.

.280 mm is what the lash is right now on 5 cylinders and one is about .250 mm and those cylinders with that much lash already have a 260 shim in them. I hope this is more clear. I'm not sure how else to explain it. It is way too loose, and I'm unsure how it could be that loose

Need to check that there is no carbon or corrosion on the valves and seats which could be holding them off or maybe all the stems have been tipped at some time and the shims were not adjusted to suit.
If all that is ok then you simply need to fit thicker shims ( they are available up to 3.2mm thick)
Your figures suggest you are looking at + 0.10 mm at around the 270 shim range to get the 0.15 clearance required.
If any shim swap lands the clearance at 0.11 /0.12mm then go the next size down to give 0.16/0.17mm.
This wont do any harm ( you can run up to 0.20mm with race cams) and will soon settle once run.

Thank you. I sprayed penetrating oil in the ports before I used the head to make sure the valves sealed and they seem ok and I have 120 plus across all four for compression so I don't believe them to be held open, was my first thought as well, hence the compression check. I was wondering if there is any way that the buckets could be different thicknesses?

Just checked some more things. If I have a 260 shim in it and still have .280mm lash that puts me at .540mm. If I put a 320 shim in that still leaves me at .220mm correct? This bike has been a thorn in my side since day 1.

Something really wrong here. Could the cams have a smaller base circle?

if you have a 260 shim that is 2.60mm, and if the gap, lets call it gap because lash is something completely different over here is .280 you need to close the gap by at least .1mm a 270 shim which will take it down to .180 this will leave the gap large by.30, and you will have a noisy tappet but these close up over time, or you could put a 275 in and have a gap of .130 which will make less noise and still within specifications.

55fbomb wrote: Just checked some more things. If I have a 260 shim in it and still have .280mm lash that puts me at .540mm. If I put a 320 shim in that still leaves me at .220mm correct? .

No.
Those figures add up to 2.88mm not .540mm.
You have mixed whole numbers and fractions.
A clearance of 0.28mm is only 0.13mm wider than the 0.15 required.
With a 2.60mm shim fitted you need a 0.13mm thicker shim which would be a 2.73mm.
Shim sizes only go up in 0.05mm increments so you either go for 270 or 275. to land on either 0.18mm or 0.13mm clearance.
As 0.13mm is in the middle of the range (0.10mm to 0.15mm) it's probably wise to go for the 275 shim and re-check after the motor has been run a few miles.

Lol you guys are right, as usual. Not sure how I ended up making that so confusing for myself. Nothing else has worked for me on this bike so I guess I just figured I would make more problems for myself that aren't real lol. Thanks guys