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Discussion Starter · #1 ·
I was playing around with my YF carter 1 bbl, and was puzzled with the Metering Rod and Jet combination. How do they affect fuel delivery and could I gain performance with an adjustment?

Also If you change the Jet do you need to change the Rod to match, or is the "one rod fits all" concept used.

The way I see it is that when the diaphragm pump is pushed down, the needle seats in the jet opening. When the pump is released the fuel, built up during the pump, is delivered to the chamber that holds the needle and jet while the needle is up, allowing fuel to flow.

So .... could the alignment of the metering rod give me better fuel delivery? and just what alignment would that be?


 

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A metering rod is what regulates the flow of fuel thru the jet. There are countless combinations possible with some carburetors, we used to spend literally days playing with different combos in the Mikunis on the Kawasakis we raced. There are, as you know, different size jets, and the metering rods come in different tapers, the taper affects how much fuel will flow at a given throttle opening. As I said, some carbs have a much larger selection than others, and most can be purchased as an optimal set from most carb performance places. Its the big boys that start messing with various combinations.

Brad
ORC Land Use Editor

and
http://home.off-road.com/~rockgarden
 
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Basicly on a jet/rod configuration the rod has a step or taper depending on the manufacture,the large step of the rod is pulled into the jet by a internal vacuum source for economy and is effective at idle and cruising.
when you step on the throttle the vacuum signal is lost and the rods are pulled further out of the jet to the smaller diameter of the rod to increase the amount of fuel for power.(this is the same principle as the power valve in holleys and other carbs)
when changing the metering rod,depending on the which diameter of the rod you change effects either economy,power,or both.
when changing the jet,it effects the entire fuel curve.

JF1
http://www.hrja.org
 

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What everybody should mention is that the term "work" and the brand "Carter" only go together in theoretical terms.

'83 CJ-7 nothing original but the tub and axle tubes
 

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Discussion Starter · #5 ·
what would a good setting be for the Rod?

Right now it is bottomed out when the throttle plate is closed, and the pump pushed down.

 
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