A few years ago I used some cup style seals and they worked great but the plunger shaft had to be turned or ground down a bit to get them to fit properly. The P/N is circled in red and a Google search should bring them up. These cups also come in different sizes and can be adapted to the 4323 Sportwins and Vacturi carbs with primer pumps.
Don’t be embarrassed by buying a Zephyr. They’re great little smooth running motors when set up right! I’ll bet you’ll end up using it more than the missus! 😀
