ok so I have a 1984 mercruiser 470....was replacing a lot of the gaskets and needed to take off the harmonic balancer to find a broke magnet and a stator....my 470 is equipped with an alternator as well. Should I replace the magnet or delete the stator? And why would I have both?
You can remove the stator if you'd like, the wires should already be disconnected if your running a belt driven alternator.
I would strongly recommend not removing the magnets attached to the inside of the balancer. Someone did that a month or two on here and then had an engine vibration. I wouldn't chance it, if it ain't broke, don't go looking for trouble.
If you have a magnet that came unglued, I would epoxy it back on in the correct spot.
You have both because the engine never came with a belt driven alternator from the factory. On the 470, Mercruiser ran a stator under the harmonic balancer similar to an outboard engine. The external voltage regulator which is water cooled and near the heat exchanger fails and is expensive to replace. The best fix is an aftermarket alternator kit, which you now have. Whoever put it in abandoned the factory set up and left it there.