Pros & Cons Outboard upgrade (carb mod)

[slabbatical]

Can anyone comment on the pros and cons of upgrading an outboard motor to get more horsepower? I've heard a carb modification can take a 9.9 to perform like a 15 hp.

I drive a 1981 Evinrude 7.5 with low hours and need just a little more umph...especially when a friend is with me. Any advice is appreciated.

Thanks

[Barnacle Bill]

Unfortunately that is an old wives tales. It takes more than just carb changes to increase to 15hp. If you compare part numbers between the two you will see what I'm talking about. A couple years ago we looked into doing that with a 9.9 Johnson. It would have cost around $850.

[grizzly]

I think it also requires new head, you know valves and such. Several years ago I was given an old 9.5 evinrude on which the throttle stop was worn off. You could get an extra quarter turn on the throttle and it would run like a batout of you know where. But I would hate to do that to a good motor. grizzly

[papasage]

change in prop pitch will give more speed and or pulling power .check out this site .
http://www.themarinedoctor.com/cgi-bin/YaBB.pl
or maby this one .
http://www.iboats.com/bbboard/bbBoard.cgi


you might git some information on supping up a motor .
yhe bore and stroke some times is the same . a different jets and reeds might give a little more . with the 2 changes