My buddy bought a 66 sport wagon with a 340 and it has a Carter 4bbl. Supposedly been rejetted for economy but it runs crappy off idle and at part throttle acceleration it somewhat spudders and chugs until you pick up some rpms and start cruising. At cruise it is smooth as silk. Any suggestions? Jetting or metering rod recommendations? Probably would help if I had a carb id# huh? I'll see if I can get one. Oh, plus, once warmed up, the idle is extremely low. To me it almost feels like 500rpm or so, maybe even lower.
idle screws - all in and back out 1.5 full turns pump arm - middle hole those are just what i use as a "start up" point on a small edelbrock , so may be close . plus : if like the edelbrocks the primary jet is the larger jet - seen those backwards . also the metering rods may not be "matched" to the primary jets - there's certain rods that are to be used with certain jets . and there are a couple choices for metering springs also . make sure the floats are not partially filled with gas - it'll run rich at idle and low speed but seem better when the engine calls for more gas . at work now , will check what edelbrock and carter info i have when i get home and see what maybe looks close . i'll figure it's probably a 600cfm range carb . that's all i can think of off the top of my head .
Remove the tiny covers over the front pistons that hold the metering rods. Sometimes the can stick in the bore. Poke them with a small screwdriver and they should push down easily and spring right back up freely. If sticking, remove and clean the 2 pistons and the bore. They must work smoothly or drivability will be really bad.
edelbrock guesstimate info : #1405 carb , man choke , performance set metering/primary jets .100 sec jets .095 metering rods .070 x .047 - orange spring #1406 , electric choke , economy set metering /primary jets .098 sec jets .095 metering rods .075 x .047 - yellow spring > metering rods , first # cruise , second # power --------------------------------------------------------- some close lookin' numbers from carter info in my federal mogul/carter tune kit : part # 16-241 metering rods ( .070 x .0475 ) part # 16-691 metering rods ( .076 x .055 ) jet part #'s ( notice last 2 carter #'s are jet size ): 120-401 ( .101 ) 120-395 ( .095 ) 120-398 ( .098 ) those numbers may be close to what you need to get going and give you some adjustment "room" . some one else may have some actual numbers from an older carter book and i have another book i can check later come to think of it . > edit - my other carb book had no carter info , my standard "kit catalog" has some info if ya get a number , and i found a kit info sheet and a carter AFB tuning spec 4-page sheet thats got some decent lookin info although i suspect it pertains to the comp series carbs but may be close on specs . > edit # 2 - also check under carb for corrosion in the heat crossover area in front of the primary's . i'm not sure about the year but thats a problem on the buick/carter combo .