whats causing primer ball to collaspe

[dale3joe]

My mercury 150 primer ball collasped on me,so i put a new one on and its doing the same thing. It seems like its only doing it when i get to about half tank of gas. Dont know why this is happening. Fuel lines are 3/8ths.

 

[JB]

Re: whats causing primer ball to collaspe

Either there is a restriction in the gas pickup or the tank vent, allowing your fuel pump to suck the ball dry.

 

[gss036]

Re: whats causing primer ball to collaspe

Could also be a clogged fuel filter.

 

[dale3joe]

Re: whats causing primer ball to collaspe

It dont happen on full tank though

 

[James R]

Re: whats causing primer ball to collaspe

Sounds like there is something floating around in the tank which floats clear of the fuel pick up when you have higher fuel level.

 

[tashasdaddy]

Re: whats causing primer ball to collaspe

between bulb and the tank. is the arrow on the bulb, pointing toward the motor????

 

[dale3joe]

Re: whats causing primer ball to collaspe

yes the arrow is pointing towards the motor. This just started happening. I dont have a inline filter,just water separator. The water separator is only a couple months old. It might be the problem im guessing.Also its only doing this on wot.

 

[wellsc1]

Re: whats causing primer ball to collaspe

I think you said you replace the primer bulb with no improvement. I agree, it's got to be a restriction between the primer bulb and the tank. When it happens again, remove the hose from the tank and determine which direction the clog is. Then work from there.

Is the tank built in the boat or removable?

 

[dale3joe]

Re: whats causing primer ball to collaspe

tank is built in.Could the water separator be causing this. I know the vent is not clogged because when i fill the boat with gas, gas comes out the vent whens its full.

 

[wellsc1]

Re: whats causing primer ball to collaspe

dale3joe,

One trick I used offshore when I had a clog and the primer bulb collapsed was to remove the hose on the take side of the bulb and blow hard back to the tank. In 8-foot sees on a 22-foot cuddy, I did what was necessary to get my family home. AFterwards, I found a collapsed ss screen the pick-up tube in the gas tank from being clogged. The assembly had to be removed from the tank to get to it though.

If you have to go that route, take the opportunity to pump out the gas and get every bit of crud out of the tank.

 

[lowell7963]

Re: whats causing primer ball to collaspe

One thought on the "half tank" sympton. If it is a built in tank, it is probably tall and a full tank of fuel will add extra head or pressure. This head pressure probably overcomes some of the blockage until the fuel is used up, the head is reduced, then the fuel pump has to do more work and can't overcome the blockage.

This continues to point to a problem in the tank.

 

[Zeeter]

Re: whats causing primer ball to collaspe

yea the water seperator could be the cause. Replace the element. Also open you fuel fill cap when this starts happening. If it fixes it you have a vent problem.

 

[dale3joe]

Re: whats causing primer ball to collaspe

Just bought a new seperator. Will try it. Hopefully it will fix the problem.