Yamaha 115HP water issues

[RangerMan5305913]

Recently I got back to my boat after letting it sit for two years. First I did was empty out all the old gas replace the gaskets, change the spark plugs and clean the carbs. After doing much of this my dad ran the motor out of water against my advice not to. But it ran none the less on land...so we take it to a launch and drop it in...it was unable to start on its own so I put some starter fluid in the carbs and primed the spark plugs...she fired right up and was able to run in neutral with the throttle open...we were able to easy on and off the throttle as we wanted...we then shut it off and were able to turn it back on on its own...but then i smelt something burning and heard something sizzling...the whole motor had overheated and stupidly neither of us noticed that no water was coming out of the motor. So to make things short I think either the impeller is shot or the water pump is shot. So now I am asking for what you guys think is the issue and how to fix it. I haven't been able to find impeller repair kits for my exact motor (1990 4 stroke Yamaha 115HP) or a water pump at all certainty no instructions on how to replace either of them. Any help would be appreciated.

Oh almost forgot...when we got it running on land the motor started to smoke from around the lift area and then a wiring harness caught on fire under the console...but the harness only went to the radio so I don't see how the motor would have anything to do with that since it's a completely different circuit (as far as I know). And once I removed the harness I was able to continue cranking on the motor (we took it to the lake alittle while afterwards and overheated as stated above)

More pictures of anything available upon request