None of the canister ports go to the EGR system. These are two separate systems.
The canister has to be matched to the carb. There were 2-port systems, and 3-port systems.
Mopes of this era had a decal on the underside of the hood detailing all the vacuum hook-ups.
IIRC 73ups had a 3-port system. One port was hooked to the fueltank vent line. Another was hooked to the carb floatbowl vent, and the last was hooked to a venturi vacuum source. I seem to recall the hose sizes all being different and also seem to remember the canister ports being marked.Marked with a single letter, indicating their path. Further, I seem to recall the highest port was for venturi vacuum.This port went to the carb well above the throttle plates, in the venturi bore.
