Here’s a pic of the shifter which has passed the throttle stop on the mag plate. I looked a little more closely, and it seems as if I removed the shift gears on the outside starboard side, and placed a washer behind it, that would basically get everything lined up again and working properly. The motor is in neutral right now (not in the pic), but I can advance the throttle to WOT.

I wonder why this happens. Wear below the powerhead on the shifter linkage to the vertical gearcase linkage shaft?