I bought a New 1989 Ranger Fisherman (bass boat padded hull, reasonable dead rise at the transom) with a 1989 (titled, some say 1988 was the last year for the tower but my title said '89) 115 I6, Merc 19P ported and cupped Laser SS prop, for 7 years and sold it to my BIL. I did most of my traveling alone, on the pad at WOT regardless of water conditions, unless really rough, trimmed out as far as I could before before speed started falling off, hearing the engine singing, and the thumping of the prop's blades hitting the surface of the water at a solid 6000 rpm. All that I changed over the years was the water jacket cover on the rear of the block once, and the surface gap spark plugs once; nothing else. Last I heard he still had the rig. There was no GPS at that time so I don't know how fast I was going as speedometers are usually in error but it was in the 50 region. That engine didn't have OT alarm so if I was running her dry, I didn't know it. I didn't have a jackplate and the engine was firmly mounted to the transom, but the way Ranger built that hull, there was about a 3" setback from the rear of the pad to the transom rear surface.
Why did I post this? Just a data point for what worked for me. Maybe I was just lucky. I didn't have an affinity for changing impellers back then either, on any of my engines going back to the late '50's.....1956 Scott Atwater Gold Top (green bottom) 10 hp, first engine dad bought new. Didn't know any better obviously, but never cost me an engine. That poor Scott, I ran it a lot in a barrel and I don't know how many times I hung it on a fence and ran it dry for a few minutes. Impeller was surely in horrible shape but it always ran and ran strong.....for a 10 hp Scott.
