2009 Yamaha F115 O/B Starter causing short

[superfitz]

I will try and be as specific as possible when I describe this problem, so I apologize for the long wall of text.
My boat has (2) 2009 Yamaha F115 4-stroke outboards. Up until recently they both have worked flawlessly and have been maintained diligently to Yamaha spec.
About 3 weeks ago I tried to turn over the starboard engine and all I got was a simple click from the starter. Then nothing. The other motor continues to work flawlessly.
Here is where the confusion comes in, when I turn the key and hear the "click" at the starter, it kills all of the electricity in the boat until I turn the key all the way off.
Just to be clear, with the engine that is operating properly, even as I turn the key all the way to start things like the radio and fish finder remain on. When I turn the "bad" engine over they both turn off and do not turn back on until I turn the key to off, not just the run position.
Battery terminal connections are wrench tight, I've tapped the starter with a hammer, and everything else obvious seems to be normal.
As I mentioned, this happened a couple of weeks ago. After a few hours of me poking around the problem disappeared and I thought it was an anomaly. I had a few weeks of good boating up until now. Since the problem has resurfaced I want to attempt a real fix then just it randomly going away.
I will monitor this thread to give updates or reply to requests. I thank you in advance for the help.

 

[Capt Ken]

Re: 2009 Yamaha F115 O/B Starter causing short

Well first, get out your big credit card. If you hit the starter with a hammer then you just trashed it. That starter has solid magnets and if you strike it with a hammer, they crumble like cookies. So that's one Boo Boo.
Your electronics is drawing off that bank of batteries and not both, that is why the other engine does not effect it. You have a bad connection on the terminals. Don't care how tight they are, are they clean and shiney. You can also have a corroded spot in the cable doing the same thing. Its a low voltage problem.
NEVER NEVER NEVER HIT A YAMAHA STARTER WITH ANYTHING HARDER THAN YOUR HAND!!!!!

 

[superfitz]

Re: 2009 Yamaha F115 O/B Starter causing short

Well first, get out your big credit card. If you hit the starter with a hammer then you just trashed it. That starter has solid magnets and if you strike it with a hammer, they crumble like cookies. So that's one Boo Boo.
Your electronics is drawing off that bank of batteries and not both, that is why the other engine does not effect it. You have a bad connection on the terminals. Don't care how tight they are, are they clean and shiney. You can also have a corroded spot in the cable doing the same thing. Its a low voltage problem.
NEVER NEVER NEVER HIT A YAMAHA STARTER WITH ANYTHING HARDER THAN YOUR HAND!!!!!

When I say "tapped it with a hammer", I really did just "tap" it with a hammer. Actually if the starter itself is the problem I have no problem replacing it as at least I can do that fix myself and it's relatively simple.

As far as the voltage problem, does that explain all of the electronics going out and staying out and until I return the key to normal? Also, if the terminal connection is the problem, why is the other motor having no problem starting when I turn on either 1 of the batteries, or both at the same time? I'm willing to clean up and even swap out the battery cables if that's definitely it. They are 4 years old and came new with the boat.