HorsePower, Old Rating Method Compared to New

I was curious as to what horsepower my 1975, 115 would be more equal to in today's engines and what would today's 115 would be in the old system?

As for HP, roughly about 5-8%.
However prop design today may be far more efficient getting the HP into the water than your old prop.
A 'new' engine with an 'old' prop may be outrun by an 'old' engine with a 'new' prop.

Interesting and thanks for the reply.

I had heard that the new 90 ETEC would perform more like the old 115.

Why is it that we do not see a 117 hp motor??--------------Because they would call it a 120 or even a 125 HP -all about marketing and MONEY !!--------------So a new 90 HP E-TEC will outperform an old worn out 115 that was likely 95 HP at the prop.

The 'old' manufacturer tolerance was in fact 10% up and down from stated.
A 90hp could then be from 81 to 99Hp.
Not uncommon on the factory to 'sort' out the good apples like selling the original built 99 as '100GT'.
Similar the 225Venom engines could make up to 248, but was still sold as 225.
Volvo Penta went the other way with their MD21 that was supposed to be 62Hp, but was never above 57!!!
I used to run all engines 3 cyl and up on my K & O dyno and not test props.
Quite interesting when encountering problems with twin installation where one engine was claimed to be 'bad'.
Technically they might both be within allowed tolerance, but with more than 20Hp allowed difference in the 100+Hp range it could be rather noticeable.
The old cross engines quite easy to 'fix' on the run, a Dremel in the intake ports behind the bypass covers!!
Even worse when two friends bought same type of boat and same engine and one went in circles around the other!!

So, Can I soup up my old crossfire with a dremel?? Tell me more!!

By the way, my old worn out 115 still has the same top speed as new, well that was until an OMC bulletin came out and said that the lead burning engines should have their timing retarded 4 deg if burining unleaded.