Replacement dual line from the tank to the motor is made by Sierra Marine. You can buy it by the foot at NAPA auto and other online places. Some only sell a 50 foot roll. You can buy fuel lines to replace the ones inside the motor at auto parts stores and small engine shops – you just need to know the inside diameter, which I think is 3/16″ for your motor, although the pressure line may be 1/8th – cut the old lines far enough from the ends so you aren’t measuring a stretched out dimension. Link to Napa dual line below.
Dave
https://www.napaonline.com/en/search?text=18-8051&referer=semantic&se=1&txtUser=