I talked to him last night. He bench tested the starter. I fact 3 of them. The one that came the motor, one that he bought from here and a 3rd that is a new aftermarket unit.
They all spin with power applied. I don't think the plunger is engaging enough or at all on any of them. The plunger can be manually pull out.
3 bad starters?
If the plunger is not engaging fully with power then how would it even be able to contact the flywheel.