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Oil in Air Cleaner Box

67670

New member
I have an 83 R-100 that I believe to be a relatively low mileage bike. It seems to collect some oil in the air cleaner box. I check in there when I change oil and it seems to have 2-3 oz's maybe. I try to add oil and keep it up on the upper line on the dipstick. Seems like there was a thread about oil consumption and oil in the air box, but I can't find it. I sort of remember that keeping your oil level on the upper end can cause this, but I could have dreamed it. Thanks for any help.
 
Right...it's best to not keep the oil topped off. Let it migrate down...don't really worry about it until it's below half. Watch how the oil level changes (or doesn't) as well as the oil in the air box. Then again, you could have a loose fitting or something with the various crankcase vent lines on the top of the engine. Worth looking into...
 
My '84 R100 would use every bit of oil over the minimum line and little to none after that. I learned to just fill it to the minimum and check it at reasonable intervals.
 
For sure the R100's will blow off some oil. I installed the deep factory pan 81-on and top up only to half between min/max. Then watch it every third tank of gas, top up a bit back to half way when it hits the min, then change the oil and start over before it gets back down to min.

If you just keep topping up to max, it will constantly blow off the top half quart through the vent system. Doesn't hurt much but is just a mess and wasteful of lube for no purpose.

It is the nature of these R100 beasties.
 
Do you check the oil with the dipstick screwed in or just resting on the top of the opening?

I've not seen oil in the box but there was a little oil film in the carbs when I removed them last.
 
Some oils burn off the additive package faster than other oils. Could be that's what's happening here.
 
Do you check the oil with the dipstick screwed in or just resting on the top of the opening?

Check the oil with the dipstick resting on the engine. Don't screw it in.

I try to keep mine in the lower half of the range on the dipstick.
 
+1 with the above.... Don't go over the halfway point between MIN and MAX and your oil blowout will significantly decrease, assuming that you don't have shot piston rings and are getting blow-by from that.

NICHT UBER MAX...
 
Look at a parts diagram and see if you have all the proper breather hoses and piping inside the airbox that go down into the carb elbows.
 
Thanks to all that responded. I will run my oil level on the low half from now on. Also I noticed that the breather tube in the top of the motor was cracked down on the air cleaner end. I didn't think it would affect this problem, but it might.
 
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