Thread: 15 HP carb on 9.9 Johnson

Can anyone help me out. Is this a good thing or should I try changing the prop first. Heard about a 10 x 7 prop he called an elephant ear. Whats your thoughts.

if you know the carb base is the same then try it, i would think you would have to re-jet though. What are you trying to accomplish ?

If you are trying to make that 9.9 a 15 it takes more than just the carb. I can't remember what all is needed but I do remember that the parts ran about $800. Its not worth it.

Just wanting to get a little more speed out of it!!

try a longer leg'd prop..before ya try that carb trick...

JAKE

Save your money. You might, just might, pick up maybe a mile or 2 per hour. Your better off changing the prop. If I remember right the WOT range is between 3000-5000 rpm with both the 10 and 15 HP.

Here is a good read on the 9.9 . I thought about doing it myself. I think this will help you make up your mind.Here is the link.

Maintaining Johnson/Evinrude 9.9 part 1

OK, tried another prop. Went from a 10 x 9.5 to a 9.25 x 8. Seems to be little or no effect. Can anyone suggest a prop size??