Home › Forum › Ask A Member › Searching for a 10 hp Johnson or Evinrude › Re: Searching for a 10 hp Johnson or Evinrude
The 9.5s measured HP at the powerhead. Older 10s measured it at the propshaft and will run circles around the 9.5s. The 9.9s began measuring HP at he propshaft, It was, I think, somewhere in the mid to late 1980s, and will run circles around the 9.5 and the older 9.9s. When the Japanese motors started propshaft HP ratings, the US manufacturers had to follow suit because their motors of close or same HP didn’t perform near as well. I have a 1957 Johnson magazine ad that proudly stated measurement at the propshaft. My 9.5 will not plane off my 14′ aluminum lightweight, open, non-decked, 1972 Starcraft with just 160 pound me in it, and neither will Mercury 9.8s I’ve worked on, but the older 10s and newer 9.9s of both brands get up and go on that boat.
Dave