Quoted from BorgDog:I would think one of those cam pieces would block the second ball from going past when it opens to move the first one.
Yes, that is how it's supposed to be. The cam should not allow a second ball past it, no matter how long the solenoid is actuated.
You may need to rotate the cam some amount (clockwise) to find out where that spot is. Another potential could be the end of the cam has been rounded off--possibly flipping the cam may solve this.
You can test this cam with the machine off, just rotating it by hand until you find the correct adjustment.
