[Bushwacker]

Welcome to the site! You're the 2nd Seafari owner to sign up in the last week or so! I've owned my '72 Seafari since 1975, mostly all original except for recent repower. If you'll send me a PM w/e-mail address, I can send you some files of brochures on that model.

I ran a 115 V-4 Evinrude for 31 years. Not fast, but was a light motor that made for a good well-balanced (not stern-heavy) combination that ran well offshore where you can't run much over 20 kts anyway when it gets rough; best prop for me was a 13 3/4 x 15P SST (cupped stainless) with cav plate raise about 1" above bottom. I averaged about 2.8 mpg over 6 trips to the Abacos, but it dropped to about 2 mpg after power trim died. It would turn 5400-5500 with a heavy load. That was rated rpm for that motor; you want to make sure motor will turn up to max rated rpm for your motor with the typical load you plan to carry. Don't know what the rated rpm is on the Merc. A couple other members on this site also run this size prop with a much newer 115 johnrudes. I tried a 13.25 x 17P, but it wouldn't turn enough rpm with the heavy load I typically ran. Newer prop designs may perform a little better but this size should get you in ballpark, assuming your gear reduction is about 2:1. Fr. Frank could probably give you better advice on Merc props. Denny