TOPIC:

I am planning to update my 75 Z1 a little by going to a 1020cc cylinder block and head. As I was looking at the Kawasaki parts site I noted that 1977 & 1978 cylinders used an O ring at the bottom of the cylinders and 1979 & 1980 did not. Can someone tell me why there were O rings on only modle two years, what was the purpose of them and will I still have to use these if I put a 78 cylinder block on my 75 cases?

Post edited by: teddycp, at: 2005/11/13 10:32

I think you'll find your 75 has o-rings around the bottom of the cylinders. I don't know for sure why the o-rings were used, I speculate to try to prevent oil seepage under the cylinder. (anybody know??) I also don't know why they would have taken them out unless it was found to be overkill.

I put a 1015 cylinder head on mine (don't know the year)and put the new o-rings on out of the gasket kit, didn't give it a second thought. There was a machined groove around the bottom of the cylinders though. I suppose then they were 77 or 78 cylinders.

Are you asking if it is a problem if you get later model 79-80 cylinders and they don't have the o-ring grooves?

Teddy, I would guess oil control as far as the o-rings go. You are in good shape using one of the blocks WITH o-rings as the newer 1015cc blocks don't fit as well on the Z1 cases and require a lot more work (grinding) to fit. You can probably use sealer in the slots where the o-rings went if you don't have the o-rings. These o-rings are a standard part of a Versah gasket kit for your bike or a 77/78 1000 I would guess.

wiredgeorge wrote:

Teddy, I would guess oil control as far as the o-rings go. You are in good shape using one of the blocks WITH o-rings as the newer 1015cc blocks don't fit as well on the Z1 cases and require a lot more work (grinding) to fit. You can probably use sealer in the slots where the o-rings went if you don't have the o-rings. These o-rings are a standard part of a Versah gasket kit for your bike or a 77/78 1000 I would guess.

i was told this same thing when i took my bike in to the shop to get running... they said since i didnt maked the wholes in the cases bigger that its pusin in on my 1000block making the rings/pistins hit... BUT they said the 1000 block wont fit in the 900 cases untill i beat it in or bored the wholes bigger... i did neither. they went right in without a problem.. so i duno