20' center console and 90hp evinrude. What will cruising speed be?

[Bushwacker]

Originally Posted by bluefishing

I am looking at a 20' seacraft center console that is powered with a 1980's evinrude 90hp. Can this motor plane this boat?. . .

Thanks

Sometime in the 1980's, all OB manufacturers changed the HP rating system from the power head to the prop. There can easily be losses of 10% or so in the water pump and gearbox, so IF that "90" is prop HP and motor has good compression, it's quite a bit stronger than the "85 HP" motors that were originally installed on new boats back in the 60's and 70's!

I'd have no concern with that rig, PLUS it will ride better and plane at lower speed than a similar boat with a modern 500 lb 4 stroke because it's CG/balance is much better!