1984 Mariner/Mercury carb float adjustment

[tommygun23]

Looking for input from a knowledgeable motor expert.

So I have a 1984 Mariner 45hp 2-stroke 4 cylinder. I have been having troubles the past couple years with what seems to be float issues. Last year the bottom carb would be pissing a constant stream of fuel out of the overflow hole. After reading various stories, I adjusted the floats so that the bottom on the non-hinged side of the float is level with where the carb bowl sits on or where the gasket is, that seemed to fix the problem. Then again this year, same problem, pissing fuel out of bottom carb overflow. So I reset them just like I did before, seemed to work, took the boat out, then it failed me. So I went back to the drawing board, played with the float and set it so it is below gasket body or where the float bowl sits, that seemed to fix the problem, when priming up the fuel it seems to hold now instead of flood. So, my question is, do I set the floats so that the non hinged side sits up just a little from the hinged side, or so the float bottom sits level with the gasket/bloat bowl seat? I've read many different settings, so its hard to determine. Boat will not run without proper adjustment.

 

[eyexer]

set it just beyond the point where the needle bottoms out in the port for the fuel intake. what I would be is really going on is that your float is sticking. If you pull the carb and take the bowl off and hold it in an upright position and raise the float and let go of it will it fall down very easily? If so do it fifteen or twenty times and make sure it does it all the time? The floats hinge can get gummed up so that they work intermittently.

 

[SupressYourself]

I'm not a "knowledgeable motor expert", or even what you'd call "helpful", but I did have a 1983 50hp Merc for several years. I had those carbs off so many times I could do it blindfolded, but never had the problem you're describing. I had problems with the needles, diaphragms, gaskets, etc, but never the floats. I finally fixed it all by buying a new boat with EFI.
Carburetors are the devil.

 

[espringers]

I find it odd you would ever need to adjust the float. This sounds like a stuck float or needle to me. Is your gas tank plastic & old?

 

[tommygun23]

Gas tank is a brand new plastic one.

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Good thing there so easy to get out...not!

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Also, is there any way to test full pressure in case it's too much? Or would that be out of the ordinary?

 

[eyexer]

pressure is never an issue. you have a needle or seat that is bad and fuel is leaking past or as I mentioned the float is sticking. the float level adjustment just doesn't change. what's fixing it temporarily is you just going into the carb and making the float work again for awhile. Been running any seafoam in it?

 

[espringers]

What eye says. And once you fix the issue you will have to adjust your float back to where it was originally. Good luck figuring that out.

 

[tommygun23]

I've never ran sea foam, looks like I'll order some new needles, unfortunately can't replace the seat.

 

[SDMF]

I've never ran sea foam

Punch yourself in the balls every time you fill up your boat without adding seafoam. Sooner or later depending upon how quick of a learner you are, you'll remember to add it into every tank.