My quads blowing oil out the crank case vent, i changed the oil, i dumped 2 quarts of ams oil in, started it up, checked the oil , and nothing was in the tank.. motor is full.. any ideas on what the problem is? thanks.

more than likely your plastic oil pump gear. take the clutch side case off and check for missing teeth. it will be right behind the clutch basket.

i checked the teeth and they are all there... any other suggestions please? thanks again.

edit- i noticed that the oil pump itself has some dents and bumps in it, could that be causing it?

Backup, you said there was nothing in the tank?
The pump is working. Sounds like you got a blockage. Either in a return line or in a port.

i know this is an old thread but i am having similar problems, did you ever find out wat it was? i dont have the black box. both of my breathers are ran into the oil tank because of the "oil pukeing" problem that coms with removing the black box, so any oil that is "puked" is recirculated into the system. any ideas?