New stator, Dead Battery 1984 Merc 90 inline 6

[superman111]

I have recently had many probs with my 1984 90 merc. I finally got them all worked out. I replaced the stator and a switch box, ran it for two days problem free, brought the boat in on the second day and went to crank it up to put it on the trailer and battery was dead. Now what i want to know is if the stator is responsible for charging the battery. If it is am I likely to be looking at my stator going out again or am I looking at a Rectifier problem, or am I way off track with both of these thoughts. I also have a low speed miss I think, however it faids away about half throttle, is there anything likely to cause this or is it likely a fouled spark plug. Any info would be much appreciated.

[j_martin]

Stator supplies ac to the rectifier, which converts it to DC. If the rectifier is bad it can eventually take out the stator. There's a rectifier testing routine in the FAQ forum.

Low speed miss on one cylinder is likely mechanical. compression, idle mixture, reed, or leakage somewhere. Could be switchbox, but not likely. Stator would take out 3 cylinders at a time.

It is remotely possible that a shorted rectifier could cause a light miss by loading down the stator.

hope it helps
John