9.9 hp Fuel pump

svey

Cadet
Joined
Apr 27, 2005
Messages
20
After running for 15-20 minutes, my motor dies. I pump the bulb a few times, it restarts fine for the same amount of time. I'm trying to pin point the problem (fuel pump or fuel line+tank). I've switch the fuel line buld portion with the same problem occuring. I don't have a spare gaz tank to switch but I do have a 1980 9.9 awaiting a cylinder job. I never had any problem with the fuel delivery with that pump/fuel tank combo. Can I switch the fuel pump from that 1980 motor to the 1976 that is giving me the fuel problem?

Tx

Yves
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 9.9 hp Fuel pump

Not the fuel pump; it runs too long for that to be a high suspect.

Ten or fifteen minutes sounds to me like poor venting or no venting of the fuel tank.

Next would be air leaking into the fuel lines or at the line connectors.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: 9.9 hp Fuel pump

I'm with JB on this one. Check all your fuel lines are tight and make certain the tank is well vented. nLoosen the cap if necessary to test it out.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 9.9 hp Fuel pump

agree, pump can not pump out of a vacuum.
 

svey

Cadet
Joined
Apr 27, 2005
Messages
20
Re: 9.9 hp Fuel pump

OMC metal tank. I don't see where the venting occures on that tank. I know that 2 little metal pins get depress when I connect the fuel line, is that wher the venting is being done? Is there a way to clean on make sure air is getting in the tank?

I will try running the engine with a loosen cap. I've switch the old fuel line connection with a new one getting the same result (complete new assembly). I don't think it is the fuel line.
 
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