Oh oh, You could be in trouble. I personally would drain the thing of old gas, fill with new and put some 50 -1 in the tank with it and then do a compression test on the engine and if good then ride it for a 100miles and see if it all holds together. (with stops to check those oil lines cause if they are "blowing off" when riding then you might have a clogged check valve. Gotta test this thing good. Make sure it's going to work IMO.