i just bought a 99 ZX7R and i went to replace the air cleaner. i noticed that the airswitch and the silencer intake where missing. it's my understanding that these items act like a one way valve to release pressure from the crank case, while containing the oil. well the lines that lead to the missing items where plugged of. wouldn't this built pressure in the crank case? Also, do i have to buy these 2 missing items for $150 or can i just connect all the lines and vent them at a level above the crank case. i figured this would be an economical way to let it breathe, but i didn't know if without the air switch valve the ZX7R would build up so much pressure that it would push oil out the open vent i'd rig up? Does anyone have any knowledge/experience with this issue.

 

My 95 ZX7 has small filter on the breather in place of the tube that used to o to the air box. I am not sure about the air switch or what it is.

 

Like notstock said I think you can get away with what your trying to do, just put a breather on it to keep junk out of your engine...