Sputter
The leather around the accelerator pump plunger "likes" to shrivel-up because of all the damned ethanol that's in today's pump gas . Living in California , I see this firsthand quite frequently ! We have the worst gasoline here !
Rebuilding a Carter BBD is such a simple deal ; three main parts to the carb (Air Horn , Fuel Bowl and Throttle Body ) ; a finger-grasp of gaskets ; a couple of "Jesus Clips" ; Metering Rods (easily snapped or broken , so handle them like a Fabrege Egg !) and other basic items .
Residing in Arizona , you have access to real carb cleaners ; no need to "dip" the parts .
While you're at it , check the vacuum lines to the vapour canister (again , be careful as the phenolic plastic hose nipples are quite brittle after 40 years ! ) and replace its filtre , which is at the base .
Also , how's the EGR ? Is it clogged with carbon ?