carbs dripping gas

[PensacolaJason]

I just recently rebuilt my carbs with new gaskets and such and now I am having an issue with it hesitating when trying to give it gas. It idles just fine. When I pulled off the motor cowl there was a puddle of gas in front beneath the carbs. And I found that quite a bit of gas is dripping out of the hole in the front (see attached picture). I made sure that the floats were set correctly by the manual, so I'm not sure what would cause gas to drip out of these holes. When I trim the motor up the gas just pours out of each hole.

 

[Bosunsmate]

Prime the fuel bulb with engine off, gas coming out?
SOunds like the float or valve is wrong, i always make mine close a bit earlier than whats recommended

 

[gm280]

While the float can be set properly, the actual needle valve can be faulty. Did you replace the needle AND seat when rebuilding the carb? If not, you need too. If you did, is the new needle and seat properly installed. Other then those three things, there is no other way for fuel to be coming out of the carb. You may need to go back in the carb and recheck everything again... JMHO!

 

[bonz_d]

What engine is this? I do know that the 2 cylinder 50 - 60 hp have a notorious small leak and you will find that there is a vacuum hose from the carb cover to the intake manifold that is supposed to suck that fuel back into the engine.

 

[Crosbyman]

did you do a blow test into the carb while holding it upside down.... air should not flow in if the jet closes properly

 

[PensacolaJason]

What engine is this? I do know that the 2 cylinder 50 - 60 hp have a notorious small leak and you will find that there is a vacuum hose from the carb cover to the intake manifold that is supposed to suck that fuel back into the engine.

Its a 1987 Evinrude E120TXCUR 120hp Outboard.

 

[PensacolaJason]

While the float can be set properly, the actual needle valve can be faulty. Did you replace the needle AND seat when rebuilding the carb? If not, you need too. If you did, is the new needle and seat properly installed. Other then those three things, there is no other way for fuel to be coming out of the carb. You may need to go back in the carb and recheck everything again... JMHO!

Yep, I replaced everything but the float itself. After rebuilding each one I would turn it upside down to make sure the float and needle were moving and not sticking.

 

[PensacolaJason]

Prime the fuel bulb with engine off, gas coming out?
SOunds like the float or valve is wrong, i always make mine close a bit earlier than whats recommended

When I squeeze the bulb (without the motor on) they don't seem to leak until I trim the motor up and then they start dripping a bunch of fuel.

 

[Bosunsmate]

When I squeeze the bulb (without the motor on) they don't seem to leak until I trim the motor up and then they start dripping a bunch of fuel.

"dont seem too".... is the primer bulb staying very firm or does it get soft within a minute or so

 

[Fed]

Doesn't the air box catch the fuel then recycle it via a little hose at the bottom?

 

[PensacolaJason]

"dont seem too".... is the primer bulb staying very firm or does it get soft within a minute or so

The primer bulb is odd on this one. Sometimes it gets hard and sometimes it doesn't. It has always started right up and ran great even when the bulb wouldn't stay hard. I just tried to get the bulb hard and I squeezed and squeezed for a while and it wouldn't get hard, but I know those carbs are full of gas from earlier in the day when I squeezed the bulb and it got hard immediately.

 

[PensacolaJason]

Doesn't the air box catch the fuel then recycle it via a little hose at the bottom?

The airbox catches a bunch of fuel, but I can't find any return hose on this model. My old 50hp Johnson had one.

 

[Bosunsmate]

The primer bulb is odd on this one. Sometimes it gets hard and sometimes it doesn't. It has always started right up and ran great even when the bulb wouldn't stay hard. I just tried to get the bulb hard and I squeezed and squeezed for a while and it wouldn't get hard, but I know those carbs are full of gas from earlier in the day when I squeezed the bulb and it got hard immediately.

You need to look into this more, it should always get hard and remain hard.
It might be there are two faults here, a leaking valve/incorrect float and a airleak in the tank line.
Did this only happen after you did the initial carb rebuild? If so id assume its the carb that has the issue not the fuel line/tank

 

[PensacolaJason]

Here is a video I uploaded to YouTube of the issue.

 

[Fed]

I took a look at the BRP website and it seems the air silencer is drained via a pick up hose feeding into the bottom carby.
Take a look.

 

[PensacolaJason]

I have narrowed it down to only one carb that is leaking. Here is what I have done so far:
​
Rebuilt carb with new gasket kit
Replaced float, needle valve, seat and seat gasket
Replaced float
Adjusted the tab on the float to manual spec and also tried adjusting it so it closes a little early.

There is no leak when the motor is trimmed all the way down. I can prime the bulb until it gets hard and no leaks. As soon as I trim the motor up it begins leaking. With the motor trimmed up It will leak as I pump the bulb and will continue to leak for a little bit even after I stop pumping the bulb.

 

[PensacolaJason]

Deleted double post

 

[Fed]

That all sounds normal to me.

 

[Bosunsmate]

Are you saying that everytime you prime the bulb with the motor down it now goes firm unlike before?
Still odd just one carb is leaking, its not very very unusual for carbs to leak a bit when tilted but to only have one do it is a bit odd

 

[PensacolaJason]

Are you saying that everytime you prime the bulb with the motor down it now goes firm unlike before?
Still odd just one carb is leaking, its not very very unusual for carbs to leak a bit when tilted but to only have one do it is a bit odd

Yes, it seems to go firm each time now. I changed the direction of the primer bulb, based on some feedback, and it seems to have caused my priming issue to go away. And yep, it is definitely just the one carb that leaks (The video I posted earlier shows it in action). After research, it seems it is natural for a little leakage from carbs, but this carb leak seems excessive to me. This is my third outboard and I've never had a carb just leak away when titled up like this one.