when the piston travels up the breather inhales when the piston travels down it exhales. it only makes sense that if you were to drill the hole in the nipple out one size larger{this being the point of greatest restriction} some performance increase should be realized. anyone try this yet. I know it's absurdly simple but who knows ? maybe someone on here has allready tried it and had adverse effects?

Some four strokes have large breather on them already.

Enjoy,

Jim

When the engine is running there isnt any inhale as you call it. The piston ring wont seal 100% so there is whats called blowby. This is why there is a crank case vent .