What happened to the O-ring?

[brs127s]

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.

[earlfor]

The only think I can think of is that the composition of the replacement "O" ring was not the same as the original and it would not tolerate the heat. Did you use a Suzuki replacement "O" ring or an aftermarket?

Earl

[brs127s]

Everything was genuine Suzuki parts. I was considering aftermarket stuff, but my buddies convinced me to go with all stock parts.

[earlfor]

You have me "scratchin my head" :-) Another possibility may be the torque wrench. I had a couple of the "clicker" type torque wrenches and a couple of the Beam style torque wrenches. Prior to torquing my head bolts down, I checked them against each other. I found the "clicker" type waaay overtorqued the bolts. (consequently, I threw them away) Are you positive your torque wrench is accurate? The "O" ring could have been overtorqued?
Just a thought.

Earl

Everything was genuine Suzuki parts. I was considering aftermarket stuff, but my buddies convinced me to go with all stock parts.

[brs127s]

Earl,

I checked my torque wrench, and it was dead on. The guys at the automotive machine shop didn't think it was caused by overtorquing. They thought more along the line that the o-ring was faulty.

[earlfor]

Are you sure you put "O" rings in there in the first place? :-) :-) Sorry, just couldnt resist. heh heh Thats probably a better idea than any I have. I dont have a clue. :-)

Earl

Earl,

I checked my torque wrench, and it was dead on. The guys at the automotive machine shop didn't think it was caused by overtorquing. They thought more along the line that the o-ring was faulty.

[saaz]

Sounds strange. If the oring was not seat properly it would really get squashed. Otherwise it should have still been reasonable .

[Anonymous]

Sounds strange. If the oring was not seat properly it would really get squashed. Otherwise it should have still been reasonable .

That's what I was thinking - I've crimped a few O-rings in my life when they weren't in the proper place.

Dave

[brs127s]

Well, I have buttoned everything back together, and I made sure the new o-ring(genuine Suzuki) was in place. Hopefully that doesn't happen again.

[terry]

If you are using the newer metal head gasket, you aren't supposed to use the rectangular "O" ring, it's only to be used with the older fibre gaskets, which Id be surprised to see were still available from Suzuki.

I don't know what effect the newer metal gasket/"O" ring combination would actually have though, I don't imagine it would cause the symptoms you described, more likely you just accidently crimped it. Cheers, Terry. :twisted: