Just watched a Video from A1 cycles about a product they call the Ventilator.You replace the oil dip stick with this vented cap and it removes 90 % of the crankcase pressure to eliminate the oil blow by out of the air cleaner.They do a video of a bike running with a pressure gauge on the head breather,thought it read 5 lbs installed the cap and it went to zero.Had a engine builder tell me that after working on a few M8 engines he felt they produced to much crank case pressure,so maybe there is something to this product.I may get one because after a 375 ride last Saturday there was oil all over the side of my trike( and yes i run it a half a quart low to help prevent this)mostly highway at 65-70mph.