[Fr. Frank]

...From my experience, I think a properly rigged SC20 can easily break 50 mph with about 175 hp on a bracket.

Quite right Denny. I used to run a 2.0L Mercury XR4 150 that was balanced to .1 gram of reciprocating weight during re-manufacture, and got aftermarket reeds and re-jetted carbs, along with a nose-cone and low-water pickup. This motor dyno'd 193 hp on a hydro-dyno.

With my Seafari, (which is heavier than a MA or SF), this motor, and no bracket, once I got it propped right, even with my ablative bottom paint I could just touch 54 mph in the right conditions. I believe with a Hermco bracket I could have achieved 57, possibly 58 mph. (The motor did suck fuel at a prodigious rate, though, at anything over 5600 rpms)

The current Etec 175 reportedly actually produces between 188 and 195 hp at the prop. (The Etec 150 about 165 hp). So with the right prop, a nose cone and a bracket, it should easily reach 55 mph on a 20' SF with a slick bottom. And cruise at over 3.5 mpg, too.

Of course, with my 90 Optimax, I still cruise at 24 mph, but get over 5 mpg