1969 Johnson Outboard - gas spitting out of carburetor

[N2Motors]

All,

I have gas spitting out of the front of my carburetor only when the motor is running.

I can squeeze the gas ball and it will firm up not allowing me to pump more gas to carburetor bowl and thus my hypothesis is that the float/needle will seal up property and not allow me to squeeze more gas through. However, when the motor starts and runs, gas will eventually drip/squirt out of the front area (presumably a vent - as gas comes from the hole to the right of the low speed rich/lean knob) in the carburetor which is 'tube' built into carburetor assembly that comes from bottom (see finger in picture) and then wraps around top of assembly and out to front vent area.

I would have thought that if I cannot squeeze gas through bowl when not running, the float/needle seals properly, so not sure why when motor does run it leaks. I did try and take carb off, flip it over and blow through the full intake nipple, and I wasn't able to blow, so when inverted, the needle does appear to seal up....

NOTE - at the bottom of my bowl between main jet and bottom there is a cork (item #78) in the carb assembly picture. Could this be the issue vs. the float/needle?

 

[F_R]

That is the bowl vent, and obviously gas should not be squirting out of it. I don't know what else to say, except the needle & seat / float must be leaking due to vibration when running. Not a common problem, for sure.

The cork gasket washer is a necessary item, and is not the cause of your present problem.

 

[boobie]

Broken reed ??

 

[N2Motors]

Thanks guys. how would I further diagnose broken reeds?

I had had the carb rebuilt with new needle/seat 2 years ago, but I did not replace float. Maybe my float no longer floats... which is why it sealed when I turned upside down, but not when it is back installed.

Q: As I think about how the needle/seat and float work... When working normally, when priming bulb it will eventually spray a bit of gas into carb. How does the gas spray in there if the bowl is full and needle property set as theoretically everything would be sealed up. Right?

 

[racerone]

No, ---The fuel in the bowl has atmospheric pressure on it.------Comes through the vent for the bowl.----The primer bulb only fills the carburetor to the point that the float valve closes.

 

[Bosunsmate]

Hows it running? If the leaking goes away at high rpm id go with Boobie and say its the reeds

 

[N2Motors]

Thanks all. I again took apart my carbs and put in a new needle, seat, float, gaskets and when I restarted it worked like a charm! Thanks everyone for your feedback. I haven't done a river test, but it was nice to see it idle and not spit out fuel.