Nipple on the bottom of the carb should be attached to the pipe running down to the centre stand. It's for draining the float bowl or if the float bowl overflows it'll come out there. Carb should also have a breather pipe, which usually runs down to the bottom of the bike aswell. I dare say the oil pipe goes on the nipple on the side of the barrel, as that's ultimately where the oil needs to go, in too the fuel stream, but i couldn't be sure. Google's bought me no joy, except this diagram, not sure it helps though. http://www.bikechatforums.com/files/carb_116.jpg