idle mix screws, base setting?

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mac daddy mopar

mac daddy mopar

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on a thermoquad, it's been 20 years since I had to adjust one, and I can't remember how many turns to set the base mixture, and the fsm doesn't say or I'm over looking it, thanks in advance.

Mark
 
Three turns out from lightly seated gets me there every time. Just make sure to do your final tuning with a vacuum gauge.
 
thank you, I was thinking 3 and 1/2 turns out, after sleeping on it, but still wasn't sure.
 
either will work fine. as long as you get it to where it can idle.
 
well it seems to like a hair over 3 turns, idles 800 rpm, and holds a steady 9 on the vacuum gauge, I don't know the cam size, but I know it has a lot of over lap, now what can I do about the fumes? I'm talking burn your eyes and make you cry fumes, before I got the carb set, I couldn't get it to idle below 1100 rpm, but now the idle is fine, stays running in drive and starts right up, my timings set at 10 btdc, thanks.

Mark
 
Sounds like the metering rods may be outta adjustment. Find the small slotted screw right in the center of the metering rod piston. take your hand and very slightly push the piston and metering rods down until they bottom slightly and hold them in place. Then, whil;e still holding the piston slightly bottomed out, turn the screw counter clockwise until the metering rod piston stops dropping down. Then, while still holding the piston down, start to turn the screw clockwise. You want to turn the screw ONE full turn clockwise from the point the piston FIRST started to come back up. That's your base adjustment. From there, you can fine tune it. counter clockwise is lean, clockwise is rich. I would not go any more than about 1/4 turn at the time while fine tuning.



mac daddy mopar said:
well it seems to like a hair over 3 turns, idles 800 rpm, and holds a steady 9 on the vacuum gauge, I don't know the cam size, but I know it has a lot of over lap, now what can I do about the fumes? I'm talking burn your eyes and make you cry fumes, before I got the carb set, I couldn't get it to idle below 1100 rpm, but now the idle is fine, stays running in drive and starts right up, my timings set at 10 btdc, thanks.

Mark
Click to expand...
 
ALSO.......the fuel well bowls are notorious for coming loose and falling off. This could also cause your problem. Very easy fix. Just rebuild the carb and clean the mating surfaces up GOOD and then reattach the bowls with a gasoline resistant 2 part epoxy. Most people use JB weld there and it is NOT resistand to gasoline.
 
thanks I'll do that in the am, as I work 2nd shift, the carb was just rebuilt, and I let my brother use it on his truck until I got the scamp together, it worked great on his stock 318.

Mark
 
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