Well, at least it was weird to me.
I got on the water at Joe Pool last week, and fished around the state park marina for about 30 minutes or so, then when I went to fire up the big motor, I cranked it 3 or 4 times, then it all of a sudden it, the starter drive stopped engaging the fly wheel. The starter drive (I guess this is what its called) would go up, but would dropped immediately without even engaging the flywheel. I gave it a break by fishing around for another 30 minutes or so, to see if it would start, but the same thing happened again, so I called it a day. I tried it a few days later in the driveway and the motor fired up with no issues. I have fired it up several times since then, and it starts right up, but the whole experience has left me kind of weary. So my question is, does this sound like an issue with my starter or my solenoid, or something else altogether?
1984 Johnson 140 hp outboard.

Sounds like the starter shaft hung up and didn't engage the bendix fully on the flywheel. If it happens again just tap the starter "lightly" with a wrench or some other type of hand tool to see if it frees it up. A spray lubricant on the shaft and bendix mechanism might keep it from reoccurring, otherwise it may be time for a new starter.

try some spray silicone on the shaft/gears area, it will dry and leave it really slick.

sounds like just some gunk on the shaft.

Never tap the starter because you can break the permanent magnets of the field. Spray the drive bendix with penetrating oil or light weight oil.

Could be a defective engine battery cable. I had this same problem on my 75 HP Mercury and it drove me batty until the mechanic with The Boat Center here found it by just checking the cables out with a electronic tester. He had seen it before.

You have a weak starter battery. That is why it started again after a few days on the charger. Get a new battery. Same thing happens to my starter when weak.