Inline 6 150hp leaking fuel from carb

[sourbsted]

When I pump the bulb rock hard I get fuel leaking out of the carb throats. It's always done this, I have always had the idea it is normal cause it needs a rich dose of fuel to start it on a cold start. However, with on going problems with this engine I have been having, i've had to re-evaluate everything that could be possibly be wrong with it. I just put a kits through the carbs, new floats, needle&seats etc. Kit's through fuel pumps, new fuel lines from carbs to tank. I adjusted the floats according to mercury workshop manuals settings, so once I know if it is normal for the carbs to do this I can put the motor back together.
My next step will be going to the boat ramp, reversing the boat into the drink , and doing the link&sync again.

 

[Maxz695]

Re: Inline 6 150hp leaking fuel from carb

No fuel should be in the carb throats at all when priming the carb period. The needle and seat must close fully when they get full. You should remove the leaking carb and adjust the float in that carb so that the fuel flow stops before leaking occurs. You should always bench test the carb prior to reinstalling to be sure the carb is corrctly adjusted, To adjust the float level on your carb you have to tweak the lever that closes the needle (Long lever). It must be slightly bent on the section past the needle to let the little hook on the end close the needle sooner, Hope this helps

 

[Maxz695]

Re: Inline 6 150hp leaking fuel from carb

See my last post on the thread http://forums.iboats.com/mercury-mariner-outboards/rookie-question-590501.html

 

[Laddies]

Re: Inline 6 150hp leaking fuel from carb

Most side bowl carbs will dribble fuel if the primer bulb is good when you prime hard but should not leak when he engine is running.

 

[sourbsted]

Re: Inline 6 150hp leaking fuel from carb

Thanks, I done what you said max, and bent the arm a little to get the float to work better. I connected the electric fuel pump up again. It seems like it can almost handle the pressure, then the bottom carb leaks fuel. It's WAY better than before. Float adjustment must be critical then.

 

[Maxz695]

Re: Inline 6 150hp leaking fuel from carb

Yes good luck with it You might get a tiny bit of fuel due to the spring but not more than a tad. When the seat seals the fuel stops flowing. If it is to high it leaks that simple. Maybe you might want to bend the lower a tad more when you get time. I know it,s a pain but well worth having a proper fuel delivery. My 40 HP side bowls never leaked a drop.

 

[sourbsted]

Re: Inline 6 150hp leaking fuel from carb

Yeah the mariner 15hp doesn't leak on the bulb. I think my problems lie with the link& sync.

 

[Chris1956]

Re: Inline 6 150hp leaking fuel from carb

The electric fuel pump is likely causing or contributing to your problem. I recommend you go back to the OEM fuel pump for a variety of reasons, mostly having to do with safety. If the fuel line ruptures, unless the elec fuel pump has a sensor for that, the bilge will fill with gasoline and you could have a fire or worse.