Mercury Horsepower: History-Making Sea Change

[Pickinator]

I am wondering the exact year that Mercury changed from measuring horsepower at the head to the prop-shaft?
My guess is 1985, but I wouldn't bet more than a dollar on it.
Any help would be greatly appreciated.

[Dave S]

It don't matter.... they just chunnn on.....

[Merc 2.5]

82 83 latest

[dspencer]

ICOMIA Standard 28-83 was created in 1983 to address inconsistencies in hp ratings so 1984 is when it started and everyone had changed by 1985.

[Merc 2.5]

ICOMIA Standard 28-83 was created in 1983 to address inconsistencies in hp ratings so 1984 is when it started and everyone had changed by 1985.

Maybe I'm wrong but I still think its 82 83 , they did alot of block and hp change that yr and also started prop rated hp, kinda hard to explain. When new block designs ,front half ,etc. Came along in 82 83 the 225 became new 200 , 175 new 150 etc, so they had to of change the way they rate hp at that time , or if they started in 85 then they b changing hp 2 yrs or so into a run of motors. I hope this makes sense , and if I'm wrong plz explain more

[mrichartz]

'85 was when all had to meet the standard of rating at prop.
It was started in 82/83 all had to by '85


Michael

[mrichartz]

I don't remember exactly but Mercury pretty sure didn't change all at once think v6s in 82/83 and the inlines in '85..
I Was only 18 and was awhile ago so memory is fuzzy.. lol



Michael