Hp rated flywheel or prop

[61fish]

I would like to upgrade my motor. I have a 1970 85hp Evinrude which runs very well. A local guy told me this motor is really about 72hp because it was rated at the flywheel. He said now they rate them at the prop. Does any one know when this changed, what year? This would make a real difference what year and hp motor I will look at for an upgrade. I have a family of 7 in a restored tri-hull. and although this old boat will pull 4 kids in a Big Bertha tube, it is quite a load.
Any help would be appreciated

 

[rickdb1boat]

Re: Hp rated flywheel or prop

They started rating them at the prop in 1985. You can figure about a 10% difference being rated at the crankshaft. It's still over 75 HP...

 

[tashasdaddy]

Re: Hp rated flywheel or prop

sounds like you need a 90 to 115. what is the max the boat is rated for. thats the real key, don't go over that.