Converted 15 Hp 1990 Evinrude

[OptsyEagle]

So I acquired a new outboard and it's model number is E10RESC. The guy said he put a 15Hp carburetor on it to convert the 9.9 to a 15Hp. Would anyone here who is familiar with these models know if the only difference between the 1990 9.9Hp and 15Hp was the carburetor?

 

[kbait]

Yes. In 1990, the 9.9’s and 15’s both used the same exhaust tube and reed plate shims. Carb and decals are only the difference.

 

[racerone]

Find a shop with a test prop.-----See if it reaches the RPM stated in the manual.

 

[tphoyt]

Raceorne has the best idea yet.
I know a lot of people that did this back in the day and the gains were not that much.
I always called it the placebo affect.

 

[kbait]

My buddy has had a 15 Johnson longshaft from ’83 for years on a deep/wide Crestliner (14’, 35hp max rated). Trolls super slow and max 22 mph. He has shoulder issues and wanted electric start, so I found a ‘91 Evinrude 9.9 e-start longshaft, and swapped his 15 carb to it. Trolls super slow and 23 mph. Performance says it’s a 15hp..

 

[OptsyEagle]

OK thanks.

 

[909]

I've owned a few 15 conversions. And a few factory 15's.

In theory they should be the same.

But in my experience the factory 15's always outperformed the 15 conversions.

Generally the difference is so little you could put a 15 sticker on a 9.9 and the average person wouldn't know the difference.