Oil in the main jet holder

[RandyB]

I just replaced the floats and float needles in the carbs (2 screw Bing dome)on my '84 R100RT which cured the running rich problem. While in there, I removed the main jet holders. When I did, oil ran out. A blast of cleaner and the needle jet holders and needle jets fell out, all covered in oil. Nothing sticks, nothing leaks, the diaphragms are fine. Bike runs well.

Is oil in there normal? The bike started and ran fine before, no smoking, oil consumption about average for this year, condition, etc. I am planning on rebuilding this bike after I get my next one. Or do I need to move that rebuild up a bit?

[lkchris]

Some is normal as crankcase vent via airbox to carbs.

[RandyB]

Thanks. I just got off the phone with Bentonville BMW. They have an excellent airhead mech and they are very helpful. He thinks I overfilled it. His advice was to only fill it until half way between add and full when the dipstick was dropped in. He said it will puke or burn until it achieves equilibrium if it's too full. That seems to be the case with my bike. Uses oil to half down, then levels off.

He didn't seem to think it was the breather valve, which is a relief. I was not looking forward to tearing it down.

[20774]

One of the places for the "excess" oil to go is in the form of an oil mist which can go out the breather. Not to say the breather is bad...it's just doing its job.

Kurt in S.A.

[pmdave]

Even if the breather valve is working correctly, there will be some crankcase oil blown into the airbox. It gets sucked into the carbs, and often will be seen dripping from the bottom of the plastic air tubes at the carbs, especially on the right side. If you see a drop of oil on the floor under the right carb, it's probably the oil dripping down from the airbox.

It's normal, but of course overfilling the crankcase will contribute to more oil being splashed around, and more oil droplets being blown into the airbox.

pmdave

[Bigrider]

Are you sure it was oil? Water sometimes gets in there and mixes with the crud. Looks black when you see it. Taking out the jets and blasting them with carb cleaner as you did is the cure.

Dave H
Colorado Springs, Co

[RandyB]

I'm pretty sure it was just oil. I've been working in Albuquerque and haven't been able to ride. :cry It'll get an oil change, timing, valve adjustment, carb synch when I get back and then we'll see how much those improve things.