Dwell, Timing now Carb

A

AndrewGnj

New member
I've recently read mr mayben's power tune post 100 times plus every other post about points and timing, so I could do my own tune up and I've made it this far.... Fantastic! I've installed my first set of points, got the dwell set at 30 and advanced the timing per instructions......now I need to get carb tuned. I'm currently at about 1000 rpm at idle.

'72 Scout II, 345, manual transmission, Holley dist w/curved points

I think I have a Holley 23xx with side float. List - 6379, 428090-c91, manual choke.

I'm ready to throw the vacuum gauge on and try to get it tuned but there are no screws in the metering body to adjust fuel mixture. What am I missing? There are two screws low rear of carb with springs.

I know I'm missing something, so your help is appreciated!!
 
Those are the idle mixture screws in back. Before you touch them ckeck the float level by removing the brass plug on the passenger side of the float bowl. Also replace any rotten vacuum lines and clean the pcv valve and be sure it rattles.
 
Your idle speed is a bit high, especially with a manual trans. Hot engine idle speed should be about 650 rpms. I go with about 750/800 with an auto trans in park, so 1000 would still be high even in that scenario. Mechanical or centrifugal advance becomes a factor at speeds much above 800 rpms, which will influence your initial timing adjustment. Your throttle blades will also be slightly open and your carb will be transitioning between idle and part throttle. Your best results for dialing in your timing and tuning your carb will be accomplished at a lower engine speed.
 
Ok, thanks.

I will get on those vac lines, they look original, and then check that float bowl level.

Should I lower the curb idle via the screw on the side that stops the throttle arm travel before I do the mix screws?
 
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