Quoted from sk8ersublime:
Check the alignment of the optics in front of Kenny. It might need to be resoldered. The delay is likely because it is out of alignment so its not playing the audio or shaking until it hits the switch in the subway.
This would seem to be the most likely culprit. The optos could be out of alignment, or might not even be working at all. When I first got my SP, I needed to replace my optos in order to get Kenny to work properly. The ball breaking the beam between the optos should set Kenny off; otherwise, the ball needs to roll over the switch in the tunnel under the playfield to make Kenny work. Go into the Service Portal, then go to the switch test. If you pass a ball or your finger between the optos, you should see an indication on your screen. If it doesn't fire, check the alignment. Also, check to see that the wires are attached to both of the opto boards (one might have come loose). If that doesn't work, it might be time to replace the optos.
Not necessarily. When the "adult" setting is enabled, certain things happen, like when Cartman mode starts, he has the explosive farting. When it's not, it shows "Beefcake". Also, if you wait too long to launch a ball on your turn, it's possible to hear the bus driver say, "What all you all starin' at?", after which one of the characters might say "Shut up, b*tch!"; needless to say, this will not be heard when adult speech is off. Another thing that I can think of is if you have it set for coin play, and you press start without having put in coins, you will hear the bus driver say, "How'd you like to suck my a**?" One more thing is the slings will fart when Terrence and Phillip have been collected, otherwise they just laugh.
I think I have a set still lying around here. I'll take a look. I would let 'em go for less than $40. Honestly, I put them in, saw what they were about, and then took them right out. The code is not complete, so some things don't work as they should. The only thing that's very different is that there is a "carpet munching mode" (really!); If I remember correctly, it's a flipper race. I don't remember how to set it off, but it's there. Definitely not for kids.