1977 Honda CB750K - Massive oil leak at the oil filter cover. Have basically ruled out that its a bad gasket, what is the problem...

[SJ15]

I have a video of the bike for sale by another person, I'm looking at it to buy

 

[hinksy]

Is it from the head gasket or cam pucks , leaking down the front of the motor ? Or is it the oil filter housing ?

 

[SJ15]

Is it from the head gasket or cam pucks , leaking down the front of the motor ? Or is it the oil filter housing ?

Oil filter housing

 

[hinksy]

It could be a badly fitted o-ring . They have one on the bolt and a bigger one on the back , mating surface . Sometimes the bigger one will dislodge as it is put on and leak . Check that , otherwise the housing isnt sealing and it could be damaged somehow