Alternator questions

I own a 2000 Malibu VLX, and the alternator is dead. I have a dbelectrical alternator 135A, been sitting on my bench for a long time. Wondering if I can install that? I understand it is a lot bigger than the 51A one I had, but somepoint I am planning on putting a better stereo than stock but not right now. Is that a problem to have an alternator that is not being used for its capability?

Also wiring it in? I understand it is a lot bigger and the larger gauge wire is needed. Do I just hook a heavy gauge wire to the connection on the alternator (ground and bat) to the starter? And just tape off the purple, orange and ground wire that was hooked originally to the old alternator? There is a 50amp circuit breaker on the boat now, does that need to be upgraded??

Looking for a basic way of getting my boat running while I get the other one fixed at some point.

thanks

Is that a problem to have an alternator that is not being used for its capability

No, its output will be based on demand. So no issue with having more amps available then demanded.

I understand it is a lot bigger and the larger gauge wire is needed

As noted, the alternators output is based on demand, so the load on the alt will not be any different then currently, until you upgrade the stereo. So you do not need to upgrade the wire now, simply to get back on the water. But, it sounds like the alternator swap is going to require some modification to make it fit, so I would just go ahead and lay in a new larger ga cable from the alt's output post to where ever the original goes.

There is a 50amp circuit breaker on the boat now, does that need to be upgraded??

This breaker's load (current draw through it) will not change with the alternator upgrade