Keeping Oil from coming out the Crankse Breather

[mrclubike]

This is what  I did to help condense the oil mist out of the crank case blow by that ends up in the carbs (or in the case of the Cafe Types) all over everything

It is expanded aluminum sheet metal  rolled up and shoved down the passage

Just make sure their is no fragment stuck in it after cutting it
It is very soft aluminum so it wouldn't be the end of the world if a small piece got down into the pan 

I don't know if it will work completely but it has to help

This is an old trick I have used on the Hercules 1404 engine that Caterpillar used that would belch oil out of the breather
I think it was actually a factory modification    :-?

[Barry]

So it that going underneath the breather valve ?

It's like the rocker covers caps on old cars that had a coarse wire wool inside them.

[mrclubike]

Yes
 It goes down into  a large cavity under the valve

[marcmax]

I have had a piece of a brass scouring pad in mine for years. Same principle as your idea. It gives the oil mist something to collect on and then drip back into the crankcase.

[BPT]

Like reflux still column packing.  I wonder if copper would improve the flavor?
 

[georgesgiralt]

I would prefer to use plain aluminum instead of copper. Given the inside of the block is humid due to condensation, I would fear that a chemical reaction would occur between the copper and the aluminum ...
But I am a bit paranoid.

[mrclubike]

I have had a piece of a brass scouring pad in mine for years. Same principle as your idea. It gives the oil mist something to collect on and then drip back into the crankcase.

With your catch can were you able to tell if the gauze helped

[marcmax]

I had the brass gauze in place well before I removed the airbox and it drastically cut down on the amount of oil I would find in the bottom of and dripping out of the airbox. Now with the catch can, and 3-4 days a week riding, I empty less than a teaspoon of oil in a months time.

[mrclubike]

Great to hear that !!!