During my dyno run the guy crimped(with plyers) the tube that head right into the top of the motor ( i thought was a crankcase vent) it looks to be about 1/2 tube. The backfiring when off throttle stopped on the spot, when i asked him what he did he explained that that was what casues the popping, and that plugging will have absolutly no effect on the life of your bike, or performence for that matter, but it effeciently stopps the popping. he was saying that you can get the top plate with no breat off one of the ZX bikes, cant remember which one, then just get rid of it, or you can go the easy route and just plug it. I have not done it yet, and if i were you i would ask someone else, but he was 100% sure that nothing bad can result.

That is the PAIR valve or air injection system. Plugging it has been widely discussed on this board and others.