Force HP

[Bob La Londe]

It seems I recall that outboards used to be rated for horsepower at the<br />crank, and now they are rated at the prop shaft. The net difference being<br />that a newer motor actually develops more power for the same rating than an<br />older motor.<br /><br />Is that true?<br /><br />If so, at about what time did motors start being rated at the prop shaft?<br /><br />The reason I ask is that I just got my Whacko (Waco) on the water.<br /><br /> My Waco Link <br /><br />They way it is configured it is rated for a 50HP outboard. I have an older<br />Force 50 on it that I picked up from Ebay. It runs great, but I was<br />wondering if shopping for a newer motor might get me a little better push.

 

[roscoe]

Re: Force HP

Nice looking rig you got there.<br />Yes, your Force was rated at the crank, not the prop. Actual at prop rating for a properly running 50, was probably about 45hp+/-.<br /><br />There is a way to figure the loss of hp, based on the number of bearings and gears in the drivetrain. But it will come out to about 45hp.<br /><br />Engine sounds like it is running well at 5200rpm, and 30 mph ain't bad either.<br /><br />So the question is, how much money do you want to spend on a replacement engine, to pick up a possible 5hp and 2 mph??