You guys talking about the big hole sitting horizontally on a flange in the front right of the engine case? Mine is clear and open. It obviously has no function other than for manufacturing or possibly for some kind of jack, support or accessory mounting, so why worry about it? I don't even remember if my hole ever had a plug after having so many bloody things rattle off my bike! Worry not - Ride, people, RIDE!
ole dagored got it right. if you'll look closely there are other mystery holes. one on rear on intake side. one on each side at very bottom where motor mounts to frame at rear. sort of a "jig" hole --makes sure #100 lines up just like #1 did.--john