ORIGINAL: Rodney

I tend to agree with greybeard, why cycle any impurities and wear particles back through the engine again to create more wear and tear. Any microscopic particles from piston,rod,cylinder etc. will just create and/or accelerate further wear. I know most of the newer designs on 4 strokes do that but; if I were selling engines, I'd like to see the old ones wear out faster too. Now most of that goop coming back out through that breather tube is oil and byproducts from the burning of the fuel, no real value or increase in mileage as the oil does not burn, only the alcohol/methanol is burned unless you are running lean and then; you will have more serious problems as the temperature will be excessive.