Join Date: Feb 2015
Location: southern oregon
that is the crank case breather and if you still have the air box it should have a tube from it to the air box. it pulls air through the crank case to prevent a build up of fuel. it is common to just put a filter on them if the air box is deleted. if the tub to the air box is still hooked up a small amount of oil seeping is normal, even have some in the air box is ok. if it is a lot of oil the most likely cause is too much oil in the crank case. excessive blow by from bad rings will cause the case to build pressure and oil to drip out of the breather.