I want to replace the 3 prong plug on a motor (intermittent use, max 10 mins) with 14amp draw but all I have is a used plug with 18AWG wire attached. The wire to the motor is 6 ft long and 14AWG. Since the length of the 18AWG section will only be about 2" will this be a problem?
Instead of trying to used a molded on plug go buy a proper replacement plug to install on the current cable. Strip the end of the cable and install it under the screws in the plug. Black goes under the gold screw. White goes under the silver screw. Green goes under the green screw.