Horsepower conversion

[Pellis62]

Fellow boaties,
Can anyone possibly help...I am trying to work out how much extra power I am going to get from 1986 Johnson 50hp( flywheel rated) motor to a 1998 Yamaha 55hp( prop rated motor)..many thanks

 

[JB]

Re: Horsepower conversion

Howdy, pellis.

Welcome to iboats.

The '86 Johnny is rated at the prop, too. I doubt that you could find any way other than reading the numbers on the cowling to tell the difference.

 

[deejaycee_2000]

Re: Horsepower conversion

I agree with JB ......

 

[Pellis62]

Re: Horsepower conversion

Thanks,
I was mis informed that the earlier Johnsons were rated a differnet way which meant that the modern - mid 90's motors were rated by the prop which resulted in a truer measure of the horsepower( often higher)...thanks for clearing up the mis conception.

 

[JB]

Re: Horsepower conversion

JohnnyRudes switched to prop rating in the early 80s, Pellis. All were rated at the prop after 1985.