rod with spring in carb

rocket350

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Apr 18, 2009
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What does it do? It is a rod fixed into the upper carb plate. It is solid, but has a spring with two tiny clips that looks like nothing but spacers. It looks like it is seated at the base of the float bowl pushing on a brass plug with a nipple.

I pulled it out of the upper carb part, and it has a plastic plug. What does this thing do? Why is it there? I just don't get it. Since it is solid, why is ther a spring?

Sorry, but I like knowing what things do!!

Mercruiser carb for a 3.0
 

Maclin

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May 27, 2007
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6,761
Re: rod with spring in carb

:confused:Accelerator pump plunger:confused:

If it is that plunger then it will move down thru a channel as the throttle is moved forward, it squirts fuel thru the squirters at the top of the carb throat.
 

rocket350

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Re: rod with spring in carb

Thanks for the diagram, but it does not show it. But it shows the brass plug with a nipple "part # 19 power jet."

I am asuming it has to do with the safety of a cap sized boat??
 

Maclin

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Re: rod with spring in carb

nice attempt at a description but need pics or a diagram dude;)


Some carbs have a fuel bowl vent that is open when the throttle is closed, a lever moves a rubber plug up out of the vent hole. When the throttle opens the lever pushes the plug back into the hole. The only ones I am familiar with like that are automotive applications, seems to me a Marine carb would not have that type of vent hole open ever.
 

Maclin

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Re: rod with spring in carb

and... no feasible way to keep fuel in an upside down carb to my knowledge.
 

xltier

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May 20, 2004
Messages
636
Re: rod with spring in carb

Thanks for the diagram, but it does not show it. But it shows the brass plug with a nipple "part # 19 power jet."

I am asuming it has to do with the safety of a cap sized boat??

that is the power valve.the spring works against vacumn and increases fuel under low vacumn conditions.like when your calling for power.you should be able to move that rod up and down.otherwise its stuck in either the rich or lean position.vacumn should hold it up and the spring will push it down on the jet pin.http://www.oldcarmanualproject.com/...Manual/pages/64Rochester2Gmanual_0007_jpg.htm
 
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