if you have an open engine setup i would stick with two lines.... if you have a cowled set up i would use 3 lines (dual clunk).... one to fuel/defuel you would need a fuel dot http://www.hangar-9.com/Products/Def...?ProdID=HAN115 , a line to carb, and a line to the exhaust... the other option would be to use a y or t in the line...i try to stay away from that though...