Prime time

[Marc Bergmueller]

I've been losing prime in the bulb of the fuel line to my 9.9 hp 4stk outboard which causes the engine to stall. It's getting worse and I have to squeeze the bulb every 5 mins to keep it running. It seems worse at low rpms. I'd like help tracking it down. I would think it is somewhere between the bulb to fuel tank end. I have an extra long run to the engine and I'll have to build one myself. What else could make the bulb lose prime and be soft but not collapsed?

 

[Ross]

you may have a leak in the suction side of the hose or the fuel pump on the engine may be bad.

 

[RichH]

The atmospheric VENT on the remote tank is probably not open or is blocked.

Or you may have one of the 'quick connect' fittings between the tank and the OB not fully 'engaged', etc. That you have to squeeze the bulb so often I'll make the bet that the quick connect that attaches to the OB connection is the one.

Other'n that you may have a bad or failing fuel pump on the OB.

 

[Marc Bergmueller]

How could my fuel pump be bad, the motors only 13 yrs old and I put gas into every time?
Thanks guys I've give it all a try. The outboard connector is a little suspect.
Hopefully this is the last year for the outboard.

 

[Brian D]

I had the same problem on my 9.9, but also had a tiny fuel leak at the intake where the hose connects to the motor. Look to see if you have a tight seal on the intake junction. I bet you are getting air in there. Might want to clean that area really good.

 

[BobM]

The bulbs themselves are a prime source of failure. I suggest you replace it.

 

[Bill1565]

every timeI have had this problem it has been a crack in the hose past the bulb which lets the engine suck air. Down here near the equator, outboard fuel hoses only last 2 years unless you put them in the shade when not actually in use.

 

[Mike B1026]

mine was the fuel connector on the outboard. Bad o-ring seal.

 

[Bob Poff]

Replace the bulb.

I had a similar problem some years ago. Thought it was the motor and took it to the shop. They found no problem.

When I described the problem, they said could be the bulb. He said that since the fuel is delivered not in a smooth steady stream, but somewhat pulsed, the bulb has a check valve to keep the prime during the "off" period.

If the valve starts to leak, you loose your prime.

Got a new bulb. Problem gone.