EV 50HP more power?

[da61comet]

im looking for some information on a early 80's evinrude, im curently restoring a 15 1/2 foot smoker craft, the boat used to be my dads but<br />when he upgraded he gave it to me, im also planning on rebiuilding the motor on the boat, it has a evinrude 1983 50 hp on it right now, i want<br />to get a little more power out of the motor. i dont know if a rebuild will bring me to where i want. right now it has alot of hours on it and is quite worn out but still running. i have searched this topic a bit on this site and have found a few posts have been set up about getting more power but im still looking for more info. <br /><br />with a full live well and two guys is hard to keep her at a nice plane across the lake. <br />i know that the 70's and 80' evinrudes are much the same and i wanted to find out how to convert my 50 hp motor into a 70 hp motor, im looking for a kit or some tech tips on how to make the changes if it is even an option. if there is anyone out there that knows any thing about<br />this i would be greatful to hear about it.

 

[Chinewalker]

Re: EV 50HP more power?

Hi D-Man,<br /> No way to get 70 ponies out of your 50, but you may find that a fresh rebuild will get you the actual rated 50, as opposed to the tired 35 or 40 you may be getting now.<br /> You may be able to find a 2-cylinder 60hp parts list and see what's different between them and upgrade through that route, but often that means acquiring a 60hp parts motor to rob the parts from. In the end it ends up being easier to just get a 60hp or 70hp and use that rather than trying to squeeze more from a lesser motor...<br /><br />- Scott

 

[djzyla1980]

Re: EV 50HP more power?

Sure the motor is running at Optimum capacity???<br /><br />I would look at compression... and RPM's before I jumped into a rebuild.<br /><br />Thats just me though.

 

[da61comet]

Re: EV 50HP more power?

i dont think im going to have to much luck with finding a 60 hp motor for parts but im just trying to get some ideas right now. i think i will do the rebuild over the winter so i still have some time to do a bit more research.<br /><br />the motor is pretty tierd, i have done all the basic maintenece on it threw the years that my dad has had it. we used to use the boat for tubing and skiing when we were growing up to it has some hard hours on it.<br />the carbs im sure need a bit of work too, but i figured if i do all that i may as well get a complete rebuild kit for it.<br /><br />in the past i have done some mod work on sled enginges and i was hoping that an out board marine engine might be able to handle the same types of work, boring over size pisions and jetting. if its to much work i might just do the rebuild and live with it until i can find a new motor within my budget.

 

[da61comet]

Re: EV 50HP more power?

i think prop size may have something to do with the planeing, and the way the boat handles also,im thinking a stainless prop might suit my needs a bit better.

 

[Dhadley]

Re: EV 50HP more power?

In that era there was a 2 cylinder 60. The torque was so close its really really hard to tell the two apart. <br /><br />Dave is on the right track. Lets look at compression and set up. If youre set up at something like 5200 theres no sense to "hop it up" cause you aint gettin all ya can now! Those little motors love rpm.

 

[da61comet]

Re: EV 50HP more power?

are you talking rpm then?, i think average full speed across the lake im between 4500 and 4900 rpm

 

[Dhadley]

Re: EV 50HP more power?

Thats killing the motor. You need to look for another 1000 rpm. I would guess the holeshot to be lacking and economy not so great for that style motor. <br /><br />What size / style / brand prop is it?<br /><br />Are you sure the tach is right?

 

[da61comet]

Re: EV 50HP more power?

im not sure on the year right now, i have that info at home. i think it is and evinrude 50hp 1983 or 1984 twin cylinder, the prop size i think is like 13 1/2 x 17<br />does that sound correct, my dad said when he got the boat the guy he got it from had a speed prop on it and it wouldnt move anywhere whatso ever.<br />oh yeh and the boat is 15.5 foot smokercraft 1984<br /><br />how does prop size and pitch make a diffrence if you dont mind me asking.<br />im not to up to speed on the boat motor world

 

[Chinewalker]

Re: EV 50HP more power?

Hi 61Comet,<br /> Currently you're driving your boat around in 5th gear, uphill - ALL the time with that "speed" prop. A "speed" prop only works if you've got the revs to swing it. By bringing the RPM up to or a little above the rated 5500 revs, it'll be like dropping it back into 4th gear for the climb uphill. Since a boat is ALWAYS climbing uphill, it's best to prop for the higher side of the rev range. Less pitch equals more RPM (akin to dropping down a gear in your car). For most props, a 1-inch pitch drop means about 200 RPM gain is the general rule of thumb...<br />- Scott