Horsepower rating at powerhead or prop?? 85hp V4

[CaneCutter79]

I was told the horsepower rating for my 1979 85hp V4 Evinrude outboard was rated at the powerhead and not the prop and newer motors are rated at the prop, not the powerhead. Model #85995R.

If that's true, what would an equal alternative outboard be for a newer motor if I were to replace my outboard with a newer model?

My boat is rated up to 85hp so I cannot exceed this rating.

 

[boobie]

Re: Horsepower rating at powerhead or prop?? 85hp V4

That is correct, it was rated at the P/H. You can put any new mtr on your boat 85 hp and under and be legal.

 

[CaneCutter79]

Re: Horsepower rating at powerhead or prop?? 85hp V4

So what horsepower at the PH equates to horsepower at the prop? How much loss is there?

I'm thinking the closest I can get without loss is a 70hp outboard.

 

[wilde1j]

Re: Horsepower rating at powerhead or prop?? 85hp V4

5 to 7% is the number I recall for looses thru the gearcase and water pump, so an old 85 is really under 80HP.

 

[metriccrescentwrench]

Re: Horsepower rating at powerhead or prop?? 85hp V4

You can still put an 85 horse outboard on and it will be your little secret. Worst that will happen is you might gain 1 or 2 mph.

 

[samo_ott]

Re: Horsepower rating at powerhead or prop?? 85hp V4

5 to 7% is the number I recall for looses thru the gearcase and water pump, so an old 85 is really under 80HP.

I always heard 10-15% loss but I always thought that seemed high.

And OMC changed the ratings in the early 80's.

 

[Vic.S]

Re: Horsepower rating at powerhead or prop?? 85hp V4

And OMC changed the ratings in the early 80's.

As a result of the introduction of ICOMIA 28-83 Although some manufacturers did I beleive already rate engines at the prop

 

[emdsapmgr]

Re: Horsepower rating at powerhead or prop?? 85hp V4

If your boat is rated for an 85, you can put any 85 on it, regardless of how it was originally rated. The BIA permits the factory to produce engines which make hp within 10% of how they are rated-to make allowances for slight manufacturing differences. Your 1979 85 may have been one that left the factory putting out between 78 and 93 hp, depending on the factory. That's perhaps as large an allowance than the variance between prop VS crank ratings. I wouldn't worry about it.

 

[Bob_VT]

Re: Horsepower rating at powerhead or prop?? 85hp V4

The horsepower rating change for the Johhnyrudes happened in 1984........... 1983 at the powerhead ......... 1984 at the prop

 

[samo_ott]

Re: Horsepower rating at powerhead or prop?? 85hp V4

As a result of the introduction of ICOMIA 28-83 Although some manufacturers did I beleive already rate engines at the prop

Yes, I believe most of the Japanese manufacturers rated them at the prop and when they started to make a big dent in US sales in the 70's, OMC and other manufacturers had to adapt to stay competitive is what I have heard.