1971 Evinrude fuel pump

[Chad Ramssy]

I have a 1971 Evinrude 6 HP fisherman. The engine runs great when I prime it. Once the fuel float bowl runs out quits. When I disconnect the fuel supply to the carb. The fuel spits out of the line but doesn't seem like much. Does anyone know what the fuel pressure should be.

 

[racerone]

I would get the factory replacement kit ( with instructions ) to repair the pump.----Or just the diaphragm.------Fuel just spits out when pulling the cord.----Pressure depends on the strength of the PRESSURE pulse from the crankcase.

 

[F_R]

Fuel pump pressure test:
Motor on boat, in gear on the lake or with test prop in adequate test tank
Gauge tee'd into line between pump and carb
Fuel tank cap loose
Fuel tank no more that 30" below carb MAX!!
800 RPM = 1 psi
2500-3000 RPM = 1.5 psi
4500 RPM = 2.5 psi

 

[F_R]

Regardless of fuel pump condition, it won't supply enough fuel if there is ANY leak between pump and the level of fuel in tank. Air is lighter to lift than fuel.

 

[Chad Ramssy]

Great info guys. Thanks. I was thinking of putting an in line low pressure electric pump because I have been so frustrated with this issue. Desperate times lol. Tired of having to pump the primer ball.

 

[kbait]

If you can pump the primer until firm w/o leaks between primer bulb and carb, you either have a bad pump or a leak between primer bulb and fuel level in tank. If you have a metal omc tank with coupler on tank, you could have a bad o-ring in hose coupler (connected to hose), or bad o-ring in tank connector fitting (bolted to tank). At this point, hooking up a known-good tank/hose will let you know if it's the pump or not.
Electric pumps of course require un-interrupted battery power, and could be a fire risk. NOT recommended!
Good luck!

 

[racerone]

Those little pumps were used on motors from 3 to 35 HP.----For about 30 years.----For likely a 1,000,000 motors.-----Why would anyone say it is not good enuff for a 71 model 6 HP.------Find the real problem I say.

 

[Crosbyman]

if your pump is sucking air an electric pump will suck air also

you can try a whole new chinese pump for $20



first...remove the side fuel connector and hook up the hose directly to the pump pump inlet

see what happens IF OK side connector is sucking air

if not ok change the pump or get a kit for the same price :-(