OMC H.P. Ratings

[Sargent Skiff]

What year did OMC begin rating horsepower at the prop rather than at the crankshaft? How much power is absorbed by the driveline? 3%, 5%? . So, for example a FD series 18 hp Johnson would be rated today as 17, 17.5 hp?

 

[wilde1j]

Re: OMC H.P. Ratings

1985 ... gearcase is where the HP is lost ~ 5% or so.