Pete S-RCU

I have an old, but new OS .91 4 stroke with the cc breather fitting on it.
The new .91's run the cc breather into the mufler.
Can this be done with the old engines, to eliminate the oily mess on the plane?
Or, I was thinking of running the cc breather into a small tank and collect the oil, and empty it after the flight.

Any opinions?

Rodney

I'm not familiar with that model engine but what you say does not make sense. Are you sure it is run back into the muffler? Now some run it back into the intake pipe between the carb and head but never into the muffler. I've done what you said "run the breather tube into a small vented tank" and did recover a surprising amount of oil. I would not try to reuse that oil though, it was rather dirty, probably carbon but not sure of the makeup of the debre. I was never an advocate of running the breather tube back into the intake pipe as I always wondered if the contaminates (possible rust particles, carbon etc.) could possibly do some harm to the engine.

1QwkSport2.5r

You would still need to vent off excess oil but some will route the crankcase breather to the cam/lifter area for extra lube and then route a drain tube off of that to allow excess to blow out. I've read this to be more popular with Satios, but not much on an OS. I think most glow 4-strokes are starved of lubrication in the cam/lifter area and the valve train in the cylinder head. If you drip some oil in this area from time to time the breather bypass plumbing shouldn't be necessary on most engines I would think.

Pete S-RCU

I think you're right, I think it was into the intake manifold.
I'm thinking the simplest, would be a small tank to collect the oil and then dispose of it.
They kick out a surprising amount of oil, makes a big mess on the plane.

Thaks for the replies guys,

Rodney

You are correct; I did this same test just out of curiosity. I collected about 1 to 2 oz of oil out of an 8 ounce tank of fuel from the breather tube.

TomCrump

You may be disappointed in your results. On my .91 Surpass a far greater amount of oil is spewed from the muffler, than from the vent tube.

swify

I have an OS .91 4 stroke that I have had for more than 20 years, it has the crank breather vent as well. Only ran it a few times but more oil comes out of the muffler than the the crank vent as Tom pointed out.