The starter knob mount on my Koban flywheel needed some work to as sometime in its life it had been brazed back on, really brazed on.
I figured the threads in it were damaged to so I faced the flywheel so I could get the steel insert out and cut some new threads. The new insert was made out of brass hex and was threaded and brazed on the inside to hold it in place.
After some more turning and polishing, it’s now ready for a starter knob.
I don’t know if this procedure would work on your Evinrude but it might be worth a try.