i just put a new well use motor in my rage. there is a vent tube that is not needed. the motor is from like a 07 or newer nytro or vector. when i got the motor i had to change the stator cover as mine had a tube that went to the oil return on the breather. now i have a tube that come off the crankcase small one like 3/8 . the motor runs ok but you can hear the tube sucking air when you shut it off. dont know if i should plug it or not?looked on michrofische and can seem to find it does it go to the breather of a newer sled air temp scensor maybe? the hose connects to the block over by the water pump on the front towards the breather