Re: 1990 merc 115 good motor ?
I believe that's a 2+2 which you will be disappointed in. Probably better on fuel and its oil injected, but if you're into water sports its not a wise choice. Runs on 2 cylinders then kicks in to 4 as the rpm picks up. Pulling skiiers and quick holeshots is not its forte. If you just want it for fishing/cruising it would probably be ok.
If you're looking for an upgrade, go for a V6.
That said.... all newer motors have more power.
The Dyno Run ... video
My 2 cents...