Rebuilt carbs gushing out fuel

[branman1971]

I have a 1977 Mercury 70hp O/B. I rebuilt both of the carbs yesterday, (gaskets, floats, needles, everything) and when I installed them today, fuel gushes out of the intake side of the carbs when I squeeze the fuel bulb. Fuel also comes out when I crank the engine over. In the rebuild kits there are cards that tell the float setting (.690/.665) but I do not know how to make that adjustment. Is this why fuel is coming out? Because of wrong float adjustment? Thanks Guys...

 

[Laddies]

Re: Rebuilt carbs gushing out fuel

It's either float adjustment sticking or the inlets are sticking, the other could be improper assembly

 

[branman1971]

Re: Rebuilt carbs gushing out fuel

Ok, pulled the bowls and adjusted the floats, no more fuel leaks. Actually got it fired up and tried to adjust the fuel/air mixture needles. Adjusting the top carb's needle makes a difference but for some reason adjusting the bottom carb makes no difference in the tone of the motor. My repair manual should arrive tomorrow, and I will start from the beginning. Anyone know where the air/fuel mix screw should be to start with?

 

[renny1]

Re: Rebuilt carbs gushing out fuel

everyone says it should be one and a quarter to one and a half turns counterclock from lightly seated but my manual (clymer) tells me to do my 115 only one from lightly seated

 

[metalvolks]

Re: Rebuilt carbs gushing out fuel

Hey,

I am having a similar problem... I have an '82 115 Merc. How do you adjust boat carb floats? On cars its pretty straightforward, but these are different... Also, what are the tolerances I need to stay between (open and closed valve position measurement)?

Paul