1975 40HP fuel starvation problem

[livelyankee]

Sirs: My 1975 40HP electric model runs great sometimes and suffers fuel starvation sometimes. The starvation is not relieved by opening the tank vent or pumping the bulb but is by use of the choke. Filter is not plugged. Carburetor has been rebuilt. Problem seems to go away if the engine is turned off for a minute or two---I have no idea what I do to eliminate the problem.

A friend suggested b ad quick-disconnects so I check the flow thru them by unscrewing the filter and pumping fuel thru the lines---regardless of how I position the connector the flow is generous and no backpressure.

Bad pump?

 

[Paul Moir]

Re: 1975 40HP fuel starvation problem

Pumping the primer bulb up hard effectively eliminates the fuel supply line, all the quick connects, fuel pump, really everything in the fuel system before the carburetor.

Could the carb's float be getting hung up? Does it happen often enough that you could try tapping the carburetor to see if the problem goes away?

 

[livelyankee]

Re: 1975 40HP fuel starvation problem

Paul:

The float in this carburetor has stuck before which I thought I fixed with judicious use of a razor blade. The float would stick in the "down" powition such that the carburetor flooded (gas running out the throat). So not at all improbable that it is still the damn float. Tapping would help in this case so that will be the next test.

Odd that a float would stop sticking after a few minutes
--but you could say the same of any source of trouble I suppose.