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Carburetor Throttle Shaft

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What alloy material is a carburetor throttle shaft made from is it BRASS ,BRONZE OR ALUMINUM BRONZE or another form of alloy ? Where can one purchase a finished to size material to make a throttle rod from?

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Brass, any metal supplier should have suitable sizes, might help a bit more if we knew your application.

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Some are made from brass, others from steel. Some are left natural, others are flash-chromed.

 

Jon.

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The typical material is type 360 free machining brass in H02 hardness.  Outside diameter sizing of brass rod is exact, so you may find a size, like 1/4-inch, that is the right dimension.  It cuts easily and cleanly.  A difficult part of making a throttle shaft is cutting the slot for the throttle plate exactly in the middle of the shaft.  For common carbs, you may be able to buy an NOS shaft complete.

 

If your carb has a vacuum leak where the shaft goes through the body, it may be that the holes in the body are worn oversize and need to be bushed, not a simple task.  You may need to make the shaft oversized.

 

 

 

 

carb_shaft_slot.jpg

slot_milling1.jpg

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Best have it replaced by Carb king or other good rebuilder. They have oversize replacement shafts and special long reamer to true up the  holes. Much easier than trying to do it yourself.

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10 hours ago, Gary_Ash said:

"The typical material is type 360 free machining brass in H02 hardness.  Outside diameter sizing of brass rod is exact, so you may find a size, like 1/4-inch, that is the right dimension.  It cuts easily and cleanly.  A difficult part of making a throttle shaft is cutting the slot for the throttle plate exactly in the middle of the shaft.  For common carbs, you may be able to buy an NOS shaft complete.

 

If your carb has a vacuum leak where the shaft goes through the body, it may be that the holes in the body are worn oversize and need to be bushed, not a simple task.  You may need to make the shaft oversized."

 

 

 

Gary, Thank you for sharing the photos. I just received the new needle valve and seat etc. from Stan Howe for my Stromberg M4.

Next up is indeed bushing the throttle shaft. I also need to do the same with the governor valve body as well since it went through

a fire back in the day and is seized solid.

 

Seeing how the shaft is setup for cutting the slot helps a lot!

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Gary is 100 percent correct.

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Hi

Thank you for info Gary was hoping to get away from making a jig What I need is for my NOS Stromberg UUR2 carburetor I intend to use, it needs a longer than standard throttle shaft  Regards Len

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Call 413-543-9017 and ask for John. He has oversized shafts and longer shafts in stock for UU2 and UUR2 carbs, along with hundreds of other Stromberg pre war parts. 

 

The shafts are difficult to make.......more than most people realize. Don’t bother trying to do it yourself as the tooling is difficult and time consuming to make.

Edited by edinmass (see edit history)

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