2006 9.9 4 stroke stalls

[longshanks]

Father in law just bought a very nice, low-hour 2006 Merc 4-stroke 9.9. Starts and runs like a top and the mechanic that inspected it prior to our purchase gave it perfect bill of health. Problem is, after running for somewhere between 10 minutes and half hour, it stalls. Pumping the bulb will prevent it from stalling. I tried swapping out his tank and line with mine, but same problem with both tanks. We are using fresh fuel and the plugs, fuel filter, all look clean. No obvious kinks, holes, etc in fuel lines in motor. It seems like it is not pumping fuel into carb. By manually pumping fuel with the bulb, it will run forever. The mechanic that inspected it is 00s of miles away, or we'd take it back. But I think this could be a simple problem and so checking in with some of the old pros here first. Any suggestions?

 

[Guest]

Father in law just bought a very nice, low-hour 2006 Merc 4-stroke 9.9. Starts and runs like a top and the mechanic that inspected it prior to our purchase gave it perfect bill of health. Problem is, after running for somewhere between 10 minutes and half hour, it stalls. Pumping the bulb will prevent it from stalling. I tried swapping out his tank and line with mine, but same problem with both tanks. We are using fresh fuel and the plugs, fuel filter, all look clean. No obvious kinks, holes, etc in fuel lines in motor. It seems like it is not pumping fuel into carb. By manually pumping fuel with the bulb, it will run forever. The mechanic that inspected it is 00s of miles away, or we'd take it back. But I think this could be a simple problem and so checking in with some of the old pros here first. Any suggestions?

There is no suction. Either carb is clogged (less likely) or you need a new fuel pump. I would notify the mechanic and have him PayPal you the cost of the pump

 

[longshanks]

Thanks Weimed, that's what I was thinking, but wondering why the fuel pump would fail on such a new motor? And how difficult is it for the shade-tree mechanic to replace?

 

[longshanks]

Hi - replying to this old post to say that we re-built the fuel pump and the stalling is still happening. Any suggestions?

 

[longshanks]

Hi all, fuel pump is re-built and motor still stalls after a few minutes of operations. Pumping the bulb will prevent stalling. I’ve tried with different tanks and fuel lines… same result. Should I attempt a carb re-build? Any other suggestions?

 

[indybleck]

What do the fuel lines to look like, or the fuel filters? Might have an air leak or vent is bad. When you swapped out tanks, did you swap the fuel hose also, or use the same hose.

 

[longshanks]

What do the fuel lines to look like, or the fuel filters? Might have an air leak or vent is bad. When you swapped out tanks, did you swap the fuel hose also, or use the same hose.

I swapped out entire fuel tanks and lines/primer etc. based on this I am concluding it’s something with the motor, and have ruled the tank and hose out