[Spectre750]

I have a KZ750N1 Spectre 1982 and the left side O-ring is leaking oil between the the cylinder head and cylinder block, Iv'e tried to retorque the head bolts but it still leaks, it did slow down a bit though, my question is if I replace the headgasket do I have to replace the lower cylinder base gasket as well? this seems fine, dry no leaks. Any help would be appreciated, thanks.:lol:

 

[StarGate]

Can't say for certain in your case but I've replaced my head gasket and orings but didn't touch the cyl base gasket and didn't have any problems. If you can pull the head w/o moving/disturbing the cylinders then it should still be good when you go back together.

 

[Alizard]

I have a KZ750N1 Spectre 1982 and the left side O-ring is leaking oil between the the cylinder head and cylinder block, Iv'e tried to retorque the head bolts but it still leaks, it did slow down a bit though, my question is if I replace the headgasket do I have to replace the lower cylinder base gasket as well? this seems fine, dry no leaks. Any help would be appreciated, thanks.:lol:

On my 1979 KZ750 twin, you would not need to replace the base gasket. I first pulled the head on mine some years back and did a top end job and no problems at all with the stock base gasket untouched. Mine has a bolt on the base of the cylinder that keeps the cylinder in place if you pull the head.

BTW, the factory base gasket on mine was some kind of tarry rubbber material with adhesive on both sides so strong superman couldn't have pulled the cylinder loose. Unbelievable how much force it took to separate the cylinder from the crankcase when I took it apart to put in new pistons. I doubt it will loosen just from the force of pulling the head off.

Also: if yours is like mine, there is a steel tube with o-rings on each end about an inch long in the top of the cylinder that mates with the head to seal the oil there. You need to replace both the top and bottom O-rings on it, and that little sucker is a PITA to get out. This time I had the cylinder out and I had to knock it loose from underneath.

Good luck.

 

[Alizard]

Can't say for certain in your case but I've replaced my head gasket and orings but didn't touch the cyl base gasket and didn't have any problems. If you can pull the head w/o moving/disturbing the cylinders then it should still be good when you go back together.

If, by some freak of nature, your cylinder was loose enough to come free by incidental pulling on the head: you could probably seal it dead tight by raising the cylinder an inch or two and running a 1/16" bead of very good RTV sealant (I used the black Ultra high temp) on the gasket and setting the cylinder back down. Probably want to replace the O-rings down there if it does raise up.