Re: no gas 18 h.p.fastwin
Do you have the connectors and the fuel filter asembly? The connectors are marked "Fuel" and "Air". The fuel filter assmbly is marked in and out. The air line goes from the "air" side of the connector to a nipple on the bottom of the reed plate below the carburator. The fuel line goes from the "Fuel" side of the connector to the "in" side of the fuel filter and then from the "out" side of the fuel filter assembly to a nipple on the carb. If you don't have the motor side connector or the fuel filter assembly I think they are pretty easy to come by. The tank side two line connector, not so much.
5/32 Ethanol safe fuel line is what you want. Any OMC dealer will have it.
Cheers...................Todd