I may be way off base on this, but I thought i read somewhere that those valves leak, to repair use a pushrod and lapping compound to smooth the seat where the ball sits. evidently what happens,(not to me but,) oil from the tank siphons down to the crankcase when let set idle for some time. The ball in the seat is supposed to prevent this. I've heard of stupid ideas like strecthing the spring to cure, but the fault is at the ball and seat. More pressure does nothing but reduce oil from getting to your motor when it is running. my .02.

 

I recently had my head gaskets replaced on my 96' evo fxr,oil started to pour out of the crank breather,i was told this is know problem and i should rebreather thru my oiltank then vent,i did this but oil still came out of the vent,someone said that the umbrella valves might be the problem,when i asked a mechanic he said there were no valves in this model ,i've had all sorts of related problems,oil seeping out of the front base ,blue smoke from the exhausts,i took it for a hard run,left it ti cool down then took it for a local run it started backfiring violently and oil poured out of the air filter ,it's a real messi dont want to run it just in case i cause damage,can anyone advise please?????