That would be the last opposed cylinder Sportwin … model 4418 ❓
The carburetor (First designed in 1907) in easy to work of if not broken. Thousands were built, although hundreds have been scrapped, a few still turn up at garage sales. The three gaskets may e traced on gasket paper and cut out with a sharp Xacto knife. The needle valve packing was used on many models and is available from several sources. The cork float is sealed with lacquer which is dissolved by the alcohol in todays fuel. If in good shape, they may by cleaned with alcohol and then dried and sealed with super glue or fuel proof model airplane dope. If too far gone a replacement may be fashioned from a Mercury float …
The float valve should be able to shut off the fuel flow when it reaches 13/16" down from the rim of the float bowl. The check valve should seal he crankcase so fuel will not flow from the fuel passage at the rear of the valve seat. Be sure the passage is open when the valve is unseated or the outboard will not run. The primer lever will check this. Pushing the float pin (valve) down will flood the float bowl. But fuel should not drip from the air intake on the port side of the carburetor unless the check valve is unseated (raised). Valve lift is regulated by the cork bumper in the carburetor cover. This should be 9/64" for your Sportwin. I have found bottle stoppers than could be trimmed to fit in both grocery and hardware stores.
