I have a 1976 Sanyo Comet II that I recently repaired. It works well now but there is one component I just don't understand. If you look into the machine from the back and look at where the flipper is mounted (The lever in the front that you pull down on to launch the balls) there is a small white plastic boomerang that is connected to a lever that is connected to a rod that goes into the downspout that leads to the lower ball tray. Inside that downspout there is a vertical plastic piece. So when the player pulls down on the lever to shoot the ball the parts move and cause that verticle piece to move inside the downspout just a little bit.

I have no idea what this could possibly be for.

If my description doesn't make sense I'll post some pictures.

Thanks.