Finally, ready to fire. To prevent a fire or fuel spray, make sure a bypassed fuel pump is empty and disconnected from the fuel tank. We crossed our fingers and turned the key. Nothing but starter grind. Then we thought to clean out the rats'-nest-clogged exhaust pipe. Yes! The mill blew white smoke for a minute or two, burning off the cylinder oil we added. Then the exhaust cleared up and the mill chugged happily along. Now it needs a good tune-up and a cleaned-out fuel tank, but maybe we'll rethink our plans to swap out the torquey old six-banger.