What did I toast? :(

[reyb]

Was running my '89 Mercury 150 outboard and saw the tach all of a sudden go dead.
I noticed that I did not tight down the positive wire going to the rectifier. I saw it
sparking a little due to the loose connection. I'm thinking it's related to the tach going
dead. Every now and then the tach will seem to work, but only at 1500rpms and above.
Also, I get the impression that the batteries aren't getting charged because subsequent
starts seems to indicate less voltage to turn the motor over. However, the motor does
seem to be firing on all cylinders. So, anyone know if I just toasted the rectifier, tach, and/or stator?

Thanks,

Rey