Evinrude 40 hp more power

[Edson15]

can you add different carbs to a 1975 40hp rude to give it a little more jam than stock? i am new to boating and this is my first outfit. Can any mod's be made to this motor without casing too much damage? Boat is only rated for a 41kw or 55hp engine. can't afford a bigger motor right now. any suggestions.

 

[Dhadley]

Re: Evinrude 40 hp more power

Are you sure you are getting everything out of you set up now? Whats the top rpm and (true) top speed? Lets start with your existing baseline, calculate slip and go from there. <br /><br />You cant get there from here if you dont know where here is.<br /><br />Good luck!

 

[Lark40]

Re: Evinrude 40 hp more power

These are not high rev engines. If you get 4400 rpm from it, that's about it. Usually, 25-27 mph is top speed on a small boat. <br /><br />The available props have pitch settings from about 10" to 14". The 14" pitch prop on a light boat is the fastest.

 

[Jim@KSC]

Re: Evinrude 40 hp more power

Kiya -<br /><br />After getting the baseline Dhadley recommends, check your compression, then, if good...<br /> Look for power reeds <br />After all the adjustments and retaking the baseline...<br /> Prop venting <br /><br />This board is chock-full of good mechanics and ideas. You will be amazed at what you can find by searching the existing posts!

 

[sloopy]

Re: Evinrude 40 hp more power

Don't get me started..... too late!!!<br />!!<br />!<br /><br />WELL, remember when you do these upgrades you hurt the engine. It is bad for it and it is dangerous, this is what usualy happens when people who have never done it before (I have done it before but still screw up and blow rods through pistons) <br /><br />You can put a bigger expantion chamber in it, and that actualy does not hurt the engine but from what I hear it is... well, not quiet<br /><br />You can put a supercharger on it but then you have to lower compression... and some other things<br /><br />You can add bigger jets (works sometimes) <br /><br />You can bore out the cylinders and add bigger pistons<br /><br />You can add "D" Pistons<br /><br />Good luck... just buy a bigger engine....<br /><br />EDITED: Corrected a bunch of spelling and capitalization errors. Sloopy's advice on this issue must be taken with a grain of salt.