100/7 using oil

[bbelk]

Normally, the right plug will be a bit more fouled than the left because the crankcase breather dumps into the right cylinder's intake snorkel.

Both of my bike foul the left side much faster than the right. It is so bad that I try to use the center stand most of the time.

Effectively that means running oil at no more than half mast on the dipstick was a BMW recommendation.

My oil level stabilizes at about half mast. The top half the mast seems to burn/blow out pretty fast. One theory I heard was that the greater volume of air above the oil reduced the crankcase pressure.

[Mal S7]

So what is this theory about the oil rings? Do they stick? Gum? Can they be worn out before the top rings are?

[Major Softie]

My oil level stabilizes at about half mast. The top half the mast seems to burn/blow out pretty fast. One theory I heard was that the greater volume of air above the oil reduced the crankcase pressure.

Yes. The pistons displace a certain amount of air. Higher oil levels reduce the crankcase volume and thus the displacement by the pistons becomes a greater percentage of the crankcase volume. Many feel that the greatest advantage of the accessory "deep oil pans" is that the increased crankcase volume really helps with this problem (but only with an extended oil pickup so you can lower the oil level).

[barryh]

My oil level stabilizes at about half mast. The top half the mast seems to burn/blow out pretty fast. One theory I heard was that the greater volume of air above the oil reduced the crankcase pressure.

Yes....and as your two bike should have the early shallow oil pan it is a more of an issue. For your 79 R65 I did some sums and concluded that running a shallow pan at half mast gave the same air space as running a later pan at the full mark. That to me says running the early bike at no more than half mast is near essential.

[BobW]

My airheads have always run at half mast. They auto corrected any overfill quickly. At half mast they seldom drink oil except for the leaks.
Bob

[lrz]

So what do you think would happen if one of the piston rings was installed upside-down/ inside-out/wrong way 'round?

I don't know, ahem, who would've done that.

[Major Softie]

Wow, "wrong way round" would be really really hard.

I presume you are talking about the oil control rings, and it all depends on their design. I believe some are more symmetrical (and simple), while others are designed in a way that would definitely drive the oil into the cylinder if installed upside down. I'm not sure what the design of your rings is.