Quoted from PocketHoleshot:
The diverter pivots very smoothly. My thought was the extra play from that bolt was absorbing the energy of the ball and making it not go up the ramp. It seems that the timing of the diverter is too early and it rejects the ball just as it makes the turn up the ramp. Most of the time it doesn't even start going up the diverter arm. I'll try and get a video of it today and post it.
Okay. To test the sloppiness of the diverter arm, engage it via the coil plunger and wiggle the diverter arm. It should have a tad of back and forth play.
Now down at the Allen screw, that should be pretty snug. Tight enough that there’s no slop but not so tight it impedes the pivot of the mech.
Check this stuff too to make sure yours is the same:
See below for a couple more pictures to "make yours like mine"
Make sure when the ball is on the diverter and going up it, it is riding the top of the diverter and not touching the metal guide welded to the outside of the diverter rod (again test this by actuating the diverter with the coil plunger behind the back wall):
Also, when the diverter is engaged, the ball should not touch it until this point (see pic below) after it makes the turn in the ramp:
If you get rejects, it is from the diverter pinching the ball, which means you have the mech adjusted so that the diverter closes too much. Go back and redo the mech adjustments until yours looks like mine.