I’ve looked at doing this in the past. Cost was not worth it. Better off selling current motor and buying a motor with T&T.
-J.
Exactly why I suggested used parts. As an example, I added “electric start” to an older 25hp Johnson tiller (1995maybe). New parts added up to over $800, I was able to purchase everything from one source, to my door in two days, for under $250 (I believe it was closer to $200, but don’t remember off the top of my head)
If the current motor is solid and a good runner, I would not hesitate to make the investment (in used parts from a reliable source).