I've got a 24' pontoon that I rebuilt into a work barge a few months ago. I currently have it rigged with a '82 115 Evinrude that I rebuilt and propped with a 13 3/4" X 13 pitch stainless prop. I'm running right at 30mph WOT at 5,600 rpm with motor trimmed up.
I also have an early 80's 140...
I just finished rebuilding a 24' pontoon boat and put a new to me 1982 Evinrude 115 on it. Boat originally had a 1978 115 that blew last October. I picked this engine up as a replacement once I finished replacing the floor.
Took it out and ran it last week. Engine starts and runs fine...but...