Bmw r75/5 head

[lelocp]

So today i did a 140 miles and overall the bike runs pretty well, no misfiring or any hesitation. But i did notice oil leaking from the spark plug hole. I recently had to get a bigsert installed because the previous repair went south. Im starting to think the big sert is failing as well because when i remove the spark plug the insert begins to unscrew itself. My question is can I use a r75/6 head with /5 rockers because i found a head for only 150 which seems to be a pretty good deal. As for the oil leaking past the bigsert, I'm assuming i need new valve guides or rings.

[Jean]

I doubt the oil is leaking from the SP hole...If you had bad rings or guides you would be BURNING oil first, not leaking out from that location. That said (and it's curious no-opne else has answered) I'd check the gasket that is under the valve covers AND check that the valve covers are correctly mounted.

What did the buisiness end of the SP look like when you removed it? Oil would make a black mess there.

[Kurt in S.A.]

What about the 12 o'clock head bolt...tight? Porous head?

Kurt in S.A.

[lelocp]

there is no oil on the spark plug and the head bolts and valve cover seem ok. im going for a ride tomorrow and im gonna ask my father if he sees oil burning. As far as the oil leak I honestly have no idea where it can be coming from, still gotta look.

[lelocp]

so im pretty sure oil is leaking past the outside threads of the big sert. My bike runs fine and starts up with no problem but im beginning to think that something if beginning to wear like the piston rings or valve guides but i wont know until i do a leak down test.

[Major Softie]

Well, a leak-down can tell you about your compression rings, but doesn't really tell you for sure about your oil-control ring, and it tells you absolutely nothing about your valve guides.

[lelocp]

i recently had to change the exhaust valve while i was getting the spark plug thread repaired. could the exhaust valve shaft be the wrong size causing oil to leak past the valve and through the spark plug threads. Idk, any thoughts on this problem? I also should mention i did a compression test when the motor was cold and got 120 and 125 psi

[pat76r90]

try unscrewing the insert and epoxying it into place. At the worst you still need a head.

[lrz]

What about the 12 o'clock head bolt...tight? Porous head?

Kurt in S.A.

This was my experience.

As far as head porosity-as many of us are wont to do I researched the matter in excruciating detail when my stud showed pooling oil after a ride. Notably, I found Oak's reference to "head porosity" as well as others who had read the same but could not really confirm or deny the condition...I still don't understand it.

In my case, a replacement of said stud preceded the leak. I believe something went awry during the repair. That said, RTV around & into both sides of the stud remedied the situation.

[lelocp]

i also just bought a new oil pan gasket and found out one of my threads where stripped, but that was after i installed the gasket. I didnt start the bike or anything, just took off the pan and gasket. There was oil on the gasket, my question is can the gasket still be used?