Re: 1982 4.5 mercury fuel line connector
Crowley Marine . com list a fuel adaptor for the motor with part#22833. It is rather pricey, 40.00 + shipping, or you could switch it to the larger fitting by getting a large fittings with barbs, and a piece of hose, and hook them so the hose goes to the fuel filter/carb and will hang just outside the motor cowling for easy hook up. Or just run the tank hose to the carb and leave it on the motor and disconnect the hose at the tank.
JMO
Oldman570