both the roller and the black plastic cam can be purchased (maybe the plastic piece with the mark is in place -- not sure.) Recommend replacement. If used, find a roller that isn't grooved.
might find, though, that the carb still needs work. They have to be disassembled, metal parts soaked, every little opening cleaned (can of carb cleaner works, along with fine wire).
think I would take care of the cam roller issue first, then see if I could dial it in. Once tuned, the manual start would likely be fine (probably easier to crank than the older ones). I can manage them, and I'm old and lazy.
Donor motor is the way to go for elec start conversion, as described above, or find a running elec start motor for use. The Sailmaster or Yachtwin (both electrics) could be converted to regular shaft if you wanted, using the l.u. from your current motor.
