my choke/carb adjustment quit working

thom

Senior Member
I should have checked into it sooner but the carb adjustment knob was hard to turn when we got our '28 Coupe recently. The other day something gave way and it quit working, obviously not turning or pulling anything in the carb. Here's what happened. It makes sense that the failure occurred at the "weak point" in the driver. I believe the needle has been too tight in the carb requiring too much effort for the adjusting knob to turn it. I have already ordered, from Smith & Jones, a replacement driver, and some other parts I need.
 

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While waiting for my parts order, I removed the carb adjusting needle housing and needle and cleaned/polished the needle so it turns easily in the housing. I can now turn the needle with my fingers. except for when it screws down flush with the top of the housing, of course. I think all will be well when the new parts are installed.
 
Is there a brass seat for the needle or is it cast into the carb body? Mine was cast into the body. It almost looks like the part that broke was cut thin and made it fail?
 
I didn't check to see if the seat is separate or cast into the carb. I think the part failed from being "worked back and forth" over time because the needle was tight in the housing. It's free now though.
 
I should have checked into it sooner but the carb adjustment knob was hard to turn when we got our '28 Coupe recently. The other day something gave way and it quit working, obviously not turning or pulling anything in the carb. Here's what happened. It makes sense that the failure occurred at the "weak point" in the driver. I believe the needle has been too tight in the carb requiring too much effort for the adjusting knob to turn it. I have already ordered, from Smith & Jones, a replacement driver, and some other parts I need.

could you tell me how you removed the driver from the rod?
 
Good morning, Thom,
it's good to have the needle grinded into your seat a little bit. I did that with fine grinding paste for engine valves. The valve seat becomes slightly wider. As a result, the rotary needle in the seat area can be set more accurately. And it does not hang if it was accidentally turned on too vigorously.
 
could you tell me how you removed the driver from the rod?

If I understand your question correctly,,,,, you pull the driver back toward the firewall, up the choke rod, compressing the spring until it can be moved to the side off the (gav) and then take it off the choke rod. You can then unscrew the (gav) gas adjustment valve). I hope that answered what you wanted to know.
 
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