Timing rotor gear cracked at the keyway? We got ya covered with a new replacement steel timing gear for the "J" series Magneto. Always make sure what model FM Mag you have by looking at the riveted tag on the side of the unit. The "J" Magneto steel rotor timing gear is quite a bit different from it's upgrade cousin the model "X" so make sure you purchase the correct steel timing gear. Replaces F/M P/N F5952.