25HP Upgrade

[KarlG]

I have a 1995 Evinrude 25 that I would like to upgrade to a 30HP. My boat will take a 40. The Only difference I find in the engines, besides the decal, is the size of the main carb jet that is larger and must produce the extra RPM's . Anyone ever put in the larger jet....is it that easy?<br />Thanks

 

[JB]

Re: 25HP Upgrade

No, Karl, it isn't that easy. I think you will find a larger venturi in the 30hp carb, and there may well be subtle differences in port timing and ignition timing. It would be nice if we could boost hp 20% with a bigger jet and a different decal,. but . . .<br /><br />Stay with the 25 hp. My Boston Whaler 13 was rated for 40hp. It ran 25mph at w.o.t. with the OMC 25. With an OMC 40 it would go a little over 30 mph and used a lot more gas (that was an old cross-scavenged 40. A looper would probably do better). Hopping it up would compromise reliability and not get you much in performance.<br /><br />Good luck.<br />JB