B
brs127s
Guest
I am hoping someone will have an explaination for me. I had about 4000 miles on my top end rebuild, and my 850 started leaking oil at the base again. It was coming around the front stud, second from the right. I believe that would be stud number seven, according to the tightening sequence. I decided to replace all the gaskets, and throughly inspect the area where I thought the leak was coming from. Upon pulling the engine apart, all the gaskets looked good. What looked really bad was the rectangular o-ring that goes between the base and the head, around the cam-chain area. In fact, it didn't even look like an o-ring any more. it looked like a mashed black mess. The original o-ring looked nothing like this when I took it apart.
Does anyone know what might have caused this to happen? Everything was carefully assembled properly, and torqued to specs. I couldn't tell if this was the actual source of the leak. My buddy from the automotive machine shop thought it might be. We used a straight edge and check all the mating surfaces with a very fine feeler gauge. We found a couple of spots that a little low, but the gasket should seal those. I think the base gasket failed, but it was very hard to tell.
Does anyone know what might have caused this to happen? Everything was carefully assembled properly, and torqued to specs. I couldn't tell if this was the actual source of the leak. My buddy from the automotive machine shop thought it might be. We used a straight edge and check all the mating surfaces with a very fine feeler gauge. We found a couple of spots that a little low, but the gasket should seal those. I think the base gasket failed, but it was very hard to tell.