Oil in the air box, not to sound like a broken record, is pretty much normal for an airhead bike. Oil will also drip out of the carbs after along ride, so don't get upset if you see a drop or two under the carbs on occasion! I tried a method to reduce oil in the intake system,it's removing the breather housing, and putting a portion of a copper pot scrub pad in there. The oil that comes out of the breather is in an atomized state, and the copper pad gives it someplace to collect and return to the oil sump, instead of being blown into the intake system. Some owners claim that only filling the oil to the halfway point between add and full marks on the dip stick also reduces oil blow by into the intake tract.
