What's up guys , my good friend has a yz426 in supermoto trim that rides with me . He bought it used from a guy , it was pretty much stock . Previous owner had a 40 tooth rear sprocket and 16 tooth front to gear it up for the street . Gears were very long , after riding and leaving the bike overnight he would notice a drip or 2 of white/yellow oil residue on the floor dripping from the valve cover breather hose . Never thought it was any issue at all. Now my friend geared it down for stunting and backroads /woods fun , he has a 15/51 . So the bike revs out about 65-70 mph. But now, that valve cover breather is spitting out oil constantly ,we noticed it cause it was spitting oil onto the rear tire . we made a catch can out of a water bottle and it had about 1/4 inch of oil in it after a few hours . Now is this from it revving a lot higher now with the short gearing? Is it normal for the 426? He hasn't lost any oil on the dipstick . Does this bike need a catch can ? Today was the first day we went out since winter , bike stayed in the gArage all winter, started up here and there .