Horsepower Rating

[7355hpchry]

Where is the horsepower rated on my 1980 Suzuki 65, at the prop or powerhead? Some have told me all outboards before 1983 were rated at the powerhead. Other's have told me it depends on the manufacturer.

How much stronger is 65HP at the prop versus 65HP at the powerhead?

This type of info is not readily found in service or repair manuals.

 

[7355hpchry]

Re: Horsepower Rating

anyone???????????????????

 

[James R]

Re: Horsepower Rating

As a general rule the Japanese have rated their motors at the prop. To my knowledge there are no published comparisons however as with all transmissions there are losses. Ran a 1983 40HP Mariner made by Yamaha for
Mercury on a 15ft Cobia Ski boat and water skied no problem. The equivalent Mercury did not perform as well.

 

[7355hpchry]

Re: Horsepower Rating

As a general rule the Japanese have rated their motors at the prop. To my knowledge there are no published comparisons however as with all transmissions there are losses. Ran a 1983 40HP Mariner made by Yamaha for
Mercury on a 15ft Cobia Ski boat and water skied no problem. The equivalent Mercury did not perform as well.

So the Mariner/Yamaha was prop rated and the Merc was Powerhead rated?

 

[James R]

Re: Horsepower Rating

That is what I was told. It is my experience,down the years, Japanese engines size for size appear to deliver more power and have been faster.