SOHC.co.uk Forums > CB750

Head leak after rebuild

(1/5) > >>

Alimacdee2:
fit like,
regards to my 1970 CB750 cylinder head which I'm planning to skim. after a full rebuild with everything replaced I skimped on the head gasket,  after just 200 really good miles & showing good compression, I noticed the head was leaking, realised I'd fitted the wrong head gasket, DS did assure I had the correct head gasket set, should have known better! rapid learning curve on gaskets and o-rings.  I notice 4 round indentations between  2-3 and 3-4 cylinder, the main oil leak is from fitting the wrong cheap head gasket, noticed 2 of these indentations have allowed a little oil into the head,. Anyone know what these indentations on the head surface are? anyone recognise what these might be?
thanks

McCabe-Thiele (Ted):
No one has replied to your post, I know less than nothing about the CB750.

I see the small circular marks you are refering to, there appears to be no corresponding areas on the cyliner block to explain them, could the marks have been made by a tool used to either hold the cylinder head when the valves were fitted or even by a valve spring compressor by a PO?

K2-K6:
Indentations are very odd, and shouldn't be there.

Speculation, as Ted has mentioned, looks like it's been clamped or similar for some reason.

Hopefully a skim can be used to fully correct the surface for rebuild.

K2-K6:
Looking at second pic, it's also evident that weird nicks and picks indent etc are present, appear random too. Something odd/variable has happened to the surface that can't immediately be attributed to anything common to that motor.

Johnny4428:
Studied the pics but was unable to determine what could have caused these marks! Strangely the deepest marks are all to the same side. Cant think that that side of the head had been impacted with something, but looks as if it’s been clamped, perhaps G clamp type home made valve compressor? Good candidate for skimming for sure.

Navigation

[0] Message Index

[#] Next page