I have a Bison great mower. I had the same trouble with the fuel tank leaking. Took it back to Global House for tank replacement. It lasted about one season . I took it to my local repair shop and asked them if they could add a stronger fuel tank,300 baht and 4 years later no problems. I have recommended this lawn mower to my friends. It should be easy for you to obtain a primer rubber,most are the same size. Happy lawn cutting.