Re: Fleetwin fuel delivery

[Don]

quote Oakhurst:

Thanks Fleetwin I will spend some time working with it tomorrow. Is the rubber check valve under the carb the most likely problem? I took the carb off to check it, but it seems like brand new. The engine itself appears to be very original with little use.

Do you mean the rubber check valve behind the carb and intake manifold? It is possible that one or both of these is broken, but it wouldn’t be my first guess. You have to remove the carb and intake manifold in order to access these check valves, so I would check simpler things first…
The first thing I would do is remove that sintered filter in the glass bowl below the carb. Once the glass bowl is off, I would connect the fuel hose and pump the primer button several times to check fuel flow to the carb. If fuel flow seems OK, I would reinstall the glass bowl and leave out the filter element, but make sure the rubber glass bowl gasket has not fallen out of place.
Next, I would pump up the primer button and start the engine. It might be a good idea to spray the top of the tank with soap to look for external leaks. You can just keep pumping the button to keep the engine running for a few minutes to build up a little pressure in the tank. Try to run the engine at a faster speed in gear while running it on the boat. Then, let the engine stall out on its own after a few minutes, then loosen the fuel tank cap slighty to see if it has built up pressure. If the tank has built up pressure, chances are pretty good, the intake manifold check valves are OK. Keep in mind that the engine will probably sneeze and cough a lot at low speed if the tank is not pressurizing properly.
Tell us more about this engine, did you just purchase it? When was the last time it ran OK? You mention having the carb apart and it "looked clean". Have you had a look at the inside/bottom of the fuel tank? The engine is never going to run right if the bottom of the tank is fouled or rusty. Is your fuel/oil supply fresh/no water? Are you mixing at 16:1?