Not really a helpful comment, but: as a brand new boater decades ago my motor stalled when I engaged the throttle forward. I re-started, reved it up in neutral, and put the motor in reverse to blow off the prop and it ran fine but when I shifted to forward it stalled again. Repeat, repeat, repeat. Being only a half mile from the dock I decided to run in reverse to get back. As I looked for my stern line to tie up at the dock I found it was tightly drawn underwater to the lower unit. Aha, moment,