David,

Another thought...remove the flame arrestor (the metal screen on the front of the carburetor) and check that the choke (metal flap) is closing fully (blocking air flow) during start-up and opening all the way (turns horizontally allowing air to easily enter the carburetor)after you've started the engine. If not, adjust the choke lever/choke cable until it does.

David a question:

Does the engine start and run for a short period and then stall or does sputter (never running properly) and stall right from the beginning?

IMPORTANT WARNING!

Make sure to close the raw water thru-hull valve when cranking an engine that does not start right away as to avoid filling the exhaust system with raw water until it backs up into the the exhaust manifold, and into the combustion chambers of the engine.

After it starts and runs for a few seconds (5 to 10 seconds), reopen the raw water thru-hull valve. But, remember to close it again if it stalls.

The reason for this is that if the engine is not starting (burning gasoline) and creating exhaust gases, there will be no exhaust gas pressure available to force out the raw water thru the exhaust system. Thereby allowing the raw water to back up into the engine...Not a good thing!