Quoted from cfh:On these bally multi-ball games, there's a trick to prevent the problem of more than one ball in the shooter lane.
what happens, assuming everything else (see schematic) looks good, is the balls don't roll down the trough lane fast enough. And the game actual over-reacts, and you end up with more than one ball in the shooter lane. it has to do with the timing of the score motor, and the closure of the trough switches. It's not difficult to get a "perfect storm" of things, so that you get more than one ball in the shooter lane.
So there's two ways to fix this problem. One is to polish the trough metal so the balls roll in the trough faster. But probably the easier method is to play with the adjustment of the trough switches.
I'm a big advocate of having EM switches in general gaped fairly close. This provides a good wiping motion on the switches, which helps keep them clean (and the game running consistently well over a long period of time.) But with the bally multi-ball trough switches, you can't do this. The switches must have a fairly wide gap. If they don't, the timing of the balls rolling down the trough can make it so you end up with more than one ball in the shooter lane.
I had a similar problem with my Fireball with the trough lane feed speed & score motor timing.
Their wasn't two ball being sent to the shooter lane in my case, what happened was everything was normal except when their was a three ball multiball happening, the third multiball in play became affected once the first two drained.
As soon as that second multiball drained the game became confused with that third ball in play & features were not registering correctly or locking the ball just on that third multiball. I pulled the apron off & observed the balls were only just making it over the hump, very slow, to the trough from the outhole & in the meantime the score motor was activating before it hit the switch in the trough, I thought this may affect the sequence.
In my case the outhole kicker assembly was totally gummed up, so I pulled it apart cleaned it , fitted a new sleeve & it shot the ball through very fast as it should. The game then played 100%.
I think it's a good idea to pull apart the outhole assembly & clean it as I did, at least to rule out this possibility.
Shawnee, KS
