Carb Problem on 83 15hp Johnson HELP!

[gvguwec]

First off this motor has not been run in about 5 years, i knew it would need a carb rebuild so i tore it apart and cleaned/replaced everything included in a rebuild kit, made sure the float was set to parallel with the flange the bowl mounts to and put the bowl on. connected the fuel line and pumped the bulb and the fuel fills and overflows the bowl and comes up the jet tube. So I disassembled and put in a new needle and seat just in case i screwed up the needle while installing it in the first assembly. still does it. The float goes up and down freely when bowl is not attached, heck i can hook the fuel up and pump the bulb with the carb upside down and the bowl off (the weight of the float holding the needle down) and it stops it from filling. but as soon as i flip it over and put the bowl on the float doesnt stop it from over flowing.... Ive never had this happen in the other carbs i have rebuilt.

 

[timsmcm]

Re: Carb Problem on 83 15hp Johnson HELP!

are there pin holes in the float or are they cork and could they be binding in the upright position or some way when you put the bowl on.

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

The float is the new black plastic one as i had the cork one and it was really gummed up and i didnt want to risk the cork pieces coming apart and plugging anything.

 

[tashasdaddy]

Re: Carb Problem on 83 15hp Johnson HELP!

5 years Read the TOP SECRET file.

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

I have read all those files and still cannot get the carb to stop sending up fuel through the main jet when i pump the bulb, it just floods up through whenever i pump the bulb, and i have a new needle, seat and float that is adjusted to parallel with the bowl flange. I'm stumped.

 

[tx1961whaler]

Re: Carb Problem on 83 15hp Johnson HELP!

Try re-adjusting the float, so that the needle closes earlier. Before putting the carb back on the motor, try holding the carb upside down and blowing into the fuel inlet. It should be sealed up tight.

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

Thanks for the reply,

I just went out and disconnected the fuel line, and flipped the carb and blew into the inlet and it IS sealed up. when i reconnect the fuel line and pump the bulb with it upside down its still sealed, flip it right side up and pump and it overflows up the jet tube

 

[tashasdaddy]

Re: Carb Problem on 83 15hp Johnson HELP!

re adjust you float, make the gap opposite the hinge an little wider than the hinge side.

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

Well i have readjusted the float every which way I can think of, from adjusting it so that it is level and also above level(should close needle earlier). always still the same thing, as soon as i pump the primer bulb it sprays up the main jet. I can blow air in the gas inlet when the carb is the correct orientation but when i flip the carb over (inverted) while still blowing into the inlet the needle seals and i cannot blow into it anymore. I know I have put all the parts back into the carb according to the manual, which i have from the library, and also from the diagram that came with the rebuild kit. I also loosened the hinge up a bit incase the hinge wasnt pivoting up and down freely, still overflows. It acts like the high speed jet is so low in the bowl that the fuel is pushed up the jet tube easier than pushing the float up, the bowl never seems very full when i go to disassemble it which doesnt make sense to me.

Couple of shots in the dark....

Is there a bowl vent that I am not finding that may be plugged and as i pump the bulb the fuel comes up while the air holds the float down?

Could it be a problem with the fuel pump that is allowing the primer bulb to overpressurize the bowl and force the needle and float down and overfill the bowl?

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

Well I think the problem has to be a plugged bowl vent as I am not getting much fuel in the bowl, maybe a teaspoon in the bottom of the bowl when i disassemble after having fuel overflow out the high speed jet.

My best guess is that the fuel pumps in and air goes out the high speed jet instead of the vent until it is covered by fuel, then the air gets trapped and the incoming fuel has no place to go but up the high speed jet because the air is trapped in the bowl. So right now i have the carb soaking in seafoam to try and dissolve any blockages of the bowl vent, which I am not sure there is one but i think that is what is happening to the carb.

Does this theory make sense to anyone or am I just destined to buy a new carb?

 

[Rick.]

Re: Carb Problem on 83 15hp Johnson HELP!

With all due respect, is it possible you have the float upside down? Rick.

 

[gvguwec]

Re: Carb Problem on 83 15hp Johnson HELP!

I thought I may have done that too but I know it is right as it only fits over the internal passages one way.

 

[Rick.]

Re: Carb Problem on 83 15hp Johnson HELP!

Take a magnifying glass and have a close look at your needle and seat. They have to be perfectly clean and in good condition. The top (point) of the needle is actually rubber. Also, is the little wire retainer in place that holds the needle to the float? Rick.