air in primer bulb

[Chadgro]

I have a 15 hp evinrude from 1977.
Is it true that air in the primer bulb does not come from a problem with the fuel pump or does this sometimes let air build up in the bulb.
It seems to me that it would only come from a bad connection in the bulb/hoses/tank.
Any input would be appreciated.
Thanks

 

[mars bar]

Re: air in primer bulb

I had a similar problem, and changed the bulb. When was the last time the hose ends were changed? Maybe time for a new hose and connectors.

 

[Chadgro]

Re: air in primer bulb

About a year ago .I only tested the engine then let it sit for another year(didn't have Trailer)
A year later it seamed to leak again.
I mainly want to see if the fuel pump in the engine will not lead to air in the bulb.
Thanks
Chad

 

[mars bar]

Re: air in primer bulb

I would start checking the connections or even. It almost sounds like the line is sucking air? Might have to replace the part on the tank with the pins. Do you have a spare tank you can try? Process of elimination.

 

[Chadgro]

Re: air in primer bulb

Thanks. I'll try a new tank fitting.

 

[kbait]

Re: air in primer bulb

I don't think a bad fuel pump could do it, but the connections to the fuel pump must be secure also.

 

[Solittle]

Re: air in primer bulb

I have a 15 hp evinrude from 1977.
Is it true that air in the primer bulb does not come from a problem with the fuel pump or does this sometimes let air build up in the bulb.
It seems to me that it would only come from a bad connection in the bulb/hoses/tank.
Any input would be appreciated.
Thanks

The connectors have small rubber o rings to mate with the tank and motor. They are cheap & easy to replace. You can inspect by visual examination & pushing in a bit on the brass ball in the center.

 

[Fjbango]

Re: air in primer bulb

I'm having the same problem and it's driving me crazy. I have a 91' Proline 230 WA with a 91' 200TXRP Yamaha (200hp) and a 100 gal fuel tank.
I disconnected the hose between the fuel filter in the powerhead and the pumps (have two). connected a transparent hose and pumped gas using the primer bulb to a bucket. I can see the air bubbles flowing through the clear hose and no matter how much I squeeze the primer bulb, the bubbles seems to have no end.
I checked all joints, replaced one hose, and now I am using a small piece of clear hose in different segments of the line between the Fuel Tank outlet and the junction to the fuel pump in the engine. I am trying to isolate in which segment the bubbles appears by first time.

I have isolated the source to the fuel water separator and I am working to fix it.

Frank

 

[ezeke]

Re: air in primer bulb

Quite a few times the problem stems from the pickup tube inside the fuel tank. They are usually metal which can corrode above the fuel, allowing air to enter.

Also, be sure to oil the gasket when replacing your fuel filter cartridge.

 

[Expidia]

Re: air in primer bulb

I had the same problem on a used boat we bought last year. I picked a complete assembly up at Walmart for 10-15 bucks. Comes with line, bulb and fittings on each end.

Bring your old line and fittings with you to match fittings up.

Gave the ball a couple of squeezes and it was solid as a rock. If it doesn't solve your issue you can always return it. Just open the package carefully and keep receipt.

 

[Joe Reeves]

Re: air in primer bulb

If you're saying that the primer bulb runs completely out of fuel, then a fuel/air leak exists between the primer bulb and the fuel supply.

If however, the primer bulb is laying in a horizontal (normal) position and you're simply inquisitive about the fuel primer bulb having its fuel quanity drop down to the half way mark..... that is the primer bulb is no longer hard and appears to have lost its full load of fuel..... that is normal.

The only way the primer bulb will stay completely full is if it is secured in a vertical position with the outlet portion of it facing up.

 

[Billy O]

Re: air in primer bulb

If you are using the metal style gas can your pick up tube probably has a crack in it. I had one that ran good on a full tank but around 3/4 it started acting up. Changed primer bulb with no difference. Pulled assembly from tank and found a real fine crack in copper tube. Also had the plastic tube in a plastic can split where it connected.

 

[bktheking]

Re: air in primer bulb

I don't think a bad fuel pump could do it, but the connections to the fuel pump must be secure also.

Yup sure can, had a 9.9 that did this to me last year, through a kit in it, problem gone.