air comming out of case vent?

[elcamino12sec]

I took the fenders off to repair a crack so the hose comming out of the case was right next to my elbow while I was adjusting the air screw on the carb. I noticed a steady stream of air comming out of the breather hose on my elbow. When I rev up the engine it really blows allot of air. I always thought the crank case was supposto make vacuume? The hose comes out of the case and into a "T" that goes into the airbox and spits and the other goes along the frame into the atmosphere. 1985 200s

[hondahaulic]

that is the blow-by from what gasses are leaking past your piston. If your motor has good compression and still runs well, your probably fine but it could be a sign of needing new piston rings.