Bruce saysMost "modern" 10 HP motors will eat the old 20HP ones.

Total nonsense bruce. I'll put my older motors up against ANY "newer" motor of
equal horsepower. They will run circles around them. EG: My stock 25hp (1954)
Johnson runs my Wolverine twin cockpit runabout 36.1(GPS) with 2 people. So
far it's outrun most of the newer 40-50 hp engines on similar boats. Recently
clocked a 6 hp wizard (54) at 21.5 on a 12' alum fishing boat. 3 weeks ago, won
the international AOMC 3HP(1930 Neptune) & 5.4hp('45 zephyr) race at 18 & 22
mph respectively. I could go on, but I think you can see I believe what I say
about the "old" motors. They have more "soul" too ). As for the squirt, I'd
go with more HP. You don't have to use it all if she feels "squirrely". As to
fuel consumption, the last third (throttle) of most outboards is all
carburetion and a 20 @ 2/3 throttle will usually use less than a 10 at full
open.
Greg Sefton