I have a Zaccaria pinball game. The bonus unit has a step up/step down unit. The game was rewarding a ton of bonus points after the ball drained. Five to ten times what it should be. I took the stepper unit apart, cleaned it. It steps up fine, but after the ball drains the step down coil fires repeatedly but the plunger does not travel all the way down every time it fires. It can take up to five coil pulses before the plunger travels all the way down and engages the gearing to actually step down one step. There are three springs that resist the step down coil plunger when it fires. I have been adjusting the springs all day but I can't get the step down coil to function as it should. I'm thinking I should put in a stronger coil. The present coil is a B26-800. Any suggestions?