Kicker power versus weight on a Master Angler 20

[Fr. Frank]

I used a '71 9.9 Chrysler as a kicker on my Seafari. Weighed 67 lbs on the bathroom scale. It would push me at about 6-7 mph at WOT and 4 mph at 75% power. I changed that for an '84 15hp Chrysler (Ward's SeaKing) at 73 lbs which gave me 11 mph at WOT, and 8 mph at 75% power. (See the pic below)
With my 375lb 90 Optimax on a 20" transom, I got tired of the water that would wash over the transom in a following sea and run down the cable boots, making the pumps cycle on and off nearly constantly.

I dearly love having a kicker. But I won't replace mine 'til I raise the transom to 30" and replace my motor again, which may be years given how well my Opti runs.