Weird Primer Bulb / Fuel Issues

[Captain Jeff]

It is difficult to get prime and get fuel to the engine. Once primed, I can start and run the engine. If I am only running at idle or low RPMs, the fuel line will run dry. I can feel air in the primer bulb and sometimes it is firm with air and I can't even pump fuel. Other times I am pumping and pumping and it takes forever to get fuel to the primer bulb.

This is on a 1999 Johnson 115. The entire fuel system has been gone through over the past couple years. Last season I rebuilt all 4 carbs, new VRO pump, rebuilt the vapor separator and primer solenoid. New fuel line from the tank to engine and a new water separating fuel filter and bracket. I can't find any fuel leaks anywhere.

I am going to replace the primer bulb tonight but does this sound like it could be a more serious issue? Also, does the orientation of the primer bulb matter? Obviously the fuel flow arrow is pointing towards the engine but can the bulb itself be horizontal or pointing up or down? Thank you

 

[alldodge]

Sounds like the primer bulb and it does matter which way the bulb is facing so long as it is connected in the direction of flow (with the arrow)

 

[hardwater fisherman]

I have a 16 ft long fuel hose and the bulb is about 6 ft from the tank. I find pumping the bulb with the arrow pointing up helps.

 

[boobie]

Yes, the primer bulb works much better when the arrow pointing up.

 

[oldboat1]

Replacing the bulb (as planned) might resolve it. Alternatively, there might be a tank vent or fuel pickup issue.

It sounds like you have a fairly new connector in place, but I’ve had issues with the connector at the engine (smaller motor). I never completely resolved it before storing the motor, but found that leaving the motor connected seemed to work (rather than disconnecting from the motor after use). Additionally, I sometimes had to run a phillips screwdriver into the connector to (presumably) open the valve. There seemed to be a buildup of fuel between the bulb and the connector, and once that pressure was released, the connecter and primer system worked normally.