Have to prime bulb while running

[kaivorth]

Have an 89 40hp Evinrude motor.

I rebuilt the fuel pump already. When I'm on the water, the boat will not stay running for long and I'll have to manually prime the primer bulb when I'm going fast.

I'll get an oem 5/16 primer bulb and fuel lines, but is there a possibility the fuel pump still isn't working right?

Also, is there a particular fuel line brands to get?

 

[Scott Danforth]

my guess is either you have a blockage in the fuel line or your pump still isnt right.

 

[F_R]

Any leak anywhere between the fuel pump and the fuel level in the tank will admit air. That prevents the pump from lifting fuel from the tank.

 

[JohnnyGuy]

I was having intermittent fuel supply issues as well.
I replaced the fuel line from the tank to the motor with a new one... problem solved.

If you want to be sure that the fuel pump is working, pop the fuel line from the carb, being fed from the Fuel Pump. It should be spurting out some fuel indicating that the pump is working?

 

[havoc_squad]

If you want to be sure that the fuel pump is working, pop the fuel line from the carb, being fed from the Fuel Pump. It should be spurting out some fuel indicating that the pump is working?

If you mean while the engine is running? That's a safety and fire hazard and could quickly run a cylinder dry for two stroke, get some extra fuel rated hose that fits with a T fitting and put a fuel/vacuum gauge on the output side of the fuel pump secured with c hose clamps connected in line with the existing fuel hose in order to check fuel pressure.

 

[hardwater fisherman]

If your fuel line is grey and of a certain brand they can fail. I had one fail and so did my nephew. I also thought I had a fuel pump problem and swapped it out on my 4hp. Is was not until I saw my nephews fuel line that I checked mine. The photo of the fuel line is not mine but one that I found.

 

[JohnnyGuy]

If you mean while the engine is running? That's a safety and fire hazard and could quickly run a cylinder dry for two stroke, get some extra fuel rated hose that fits with a T fitting and put a fuel/vacuum gauge on the output side of the fuel pump secured with c hose clamps connected in line with the existing fuel hose in order to check fuel pressure.

Pull the fuel line from the carb and crank the motor.
Fuel should spurt out...
Engine doesn't have to be running.

 

[kaivorth]

Replaced the fuel line, rebuilt the fuel pump, tuned the linkage, cleaned the carbs. She's running mint.

The fuel line fixed my constant squeezing of bulb, and then everything else fixed my lower than normal speed

 

[DRCrowe]

Great news, glad the fuel line did the trick. I rebuilt my VRO pump earlier this year and didn't get the return spring seated correctly on the air side of the pump and it caused the same issue!

 

[dabrackmaster]

I replaced my fuel pump, clamps, lines, primer bulb, and already had my VRO bypassed. After 3 weekends of trial and error.......
..glass inline visible fuel filter had started unscrewing from removing the line and what not. Allowing air in, I almost never found it!