Bog issue FINALLY resolved

[pkbinplano]

after much tinkering I came to the concluson the top back butterfly was opening too soon. So I replaced the choke pull off diaphram that wasn't working properly. Then adjusted the air valve tension spring for the top back butterfly till it didn't bog. Very little and light tension spring so it didn't take much. Then pulled the plug out from the top of the carb and turned the adjustment out one turn which gave it more punch. Can't recall the last time the truck ran this good. Here's the link for the air valve tension spring adjustment . Pic is of the plug that needs to be pulled to access the adjustmet. Drilled a small hole maybe 1/4 deep then put a self tapping screw in and gently pulled the plug out. After adjusting just push plug back in. Maybe for the secondary metering valve ? I was told but have forgotten . All was done with carb in place. Pic is of spare carb

[geezer#99]

That plug accesses the adjustable part throttle. Apt for short. The threaded thing inside controls how deep the primary metering rods sit in the jets at idle. I've taken the top off the carb and removed the screw and cut a slot in the top for a flat blade screwdriver. The plug hole I tapped for a 3/8 inch bull plug also with a slot in it. Then you can remove the plug at your leasure and adjust the apt from the outside. CCW richer for cold weather and CW for summer time. The factory setting can be 3-6 turns out from bottom. Easily adjustable for power or economy.