Just picked up a Williams Grand Prix. Very nice shape.
Everything seems to work great except the left bonus kickout saucer.
I did a search and found tons of bonus problem with this game, but not this problem.

The right side saucer works great. It counts down the bonus and then fires both kickout holes to clear the ball.
But the left side bonus hole will count down the bonus and never fire the kickout coils.
It have cleaned and adjusted the contacts under the saucer and checked wire solder, but no luck.
What would cause the right one to work fine but the left one to just sit there?
I know the coil and circuit are fine because it fires perfectly with the right kickout.

Got it kicking out now. But the bonus stepper unit appears to stay between two rivers and not just touching one at a time. Also noticed our big red bonus arrow inserts never change sides. It always points left.

Yay. Red arrow now switching sides.
Just have to get the stepper adjusted correctly and I think it will be good.

We adjusted the EOS switch on the stepper unit. Was not opening.
That is the first thing we did to the machine when we got it as it was the biggest problem with game play.