our 88 warrior smokes a little so im boring it out .020 over and replacing the valve seals.but my question is why is there about 3 or 4 ounces of oil in the bottom of the air box sometimes?

 

Your Warrior vents the crankcase breather into the airbox. Unfortunately, they do it BEFORE the air filter, and it gets a bunch of dirt in the tube, which could get down into the engine. But...anyone who has seen a Warrior airbox with a filter that just sits there held on by nothing, knows that Yamaha had no idea what they were doing, at that point in their history!!!

Anyway, most oil in the airbox comes off the air filter, and people just don't realize it. Otherwise, is it possible you overfilled it and it puked out the excess oil? Or, have you been over some extremely bumpy terrain lately?