more speed out of 54 evinrude 7.5hp

[praisnm]

how do i get more speed out of this motor? can i get a speed prop for something like this? i have also heard of people having a 1 to 1 gear ratio on small motors too, any ideas?

 

[CATransplant]

Re: more speed out of 54 evinrude 7.5hp

There aren't really a lot of prop options for that oldster, I'm afraid. About the best advice is to have the engine running perfectly and fiddle with the trim angle, and maybe with the height of the mount.

That's a great old outboard, but it's not a racer. It's a fishing motor.

What sort of boat do you have it on?

 

[Chinewalker]

Re: more speed out of 54 evinrude 7.5hp

1:1 gear ratios were offered on some specialty racing motors - which yours is most definitely not. As CAT noted, make sure it is putting out all 7.5 ponies and call it good. If you want to go faster - get a bigger motor...
- Scott

 

[steelespike]

Re: more speed out of 54 evinrude 7.5hp

I guess my first question is what is your present speed?Original rated speed is 15.With the right boat very carefully loaded and careful setup you might approach 15.A true speed prop is meant for a very light boat (racing hull)
and would be all but useless on a regular hull.

 

[praisnm]

Re: more speed out of 54 evinrude 7.5hp

i get going right at 15mph....and i have the wrong prop...i only have a 2 blade prop...my 12ft jon boat only weighs 80lbs or so. i have to sit in just the right spot...right behind my middle seat...and that gives me the best speed. so everyone on here says i should be using a 24:1 mix....and all the boat shops say 50:1 with the oils in current day gasoline...i have only ran 24:1 would it get more speed using 50:1?

 

[rndn]

Re: more speed out of 54 evinrude 7.5hp

The only additional speed you will get by reducing the oil ratio is the speed in which you need to replace the motor.

 

[fishdog4449]

Re: more speed out of 54 evinrude 7.5hp

As stated above, its not really a go fast type. However, make sure you spark is hot and blue, carb is cleaned and operating properly, and you can try different props. 15 mph sounds great for that engine though! If you really want more speed, a newer 9.9 or 15 with a speed prop should push you pretty fast.

 

[CATransplant]

Re: more speed out of 54 evinrude 7.5hp

I found that video of you running your skinny jon boat with that 7.5. You aren't going to go faster than that with that boat and motor. It's doing all it's supposed to do. It sounds like it's running at its rated RPM at full throttle, so that's the best it's gonna do....ever.

I doubt that little jon is rated for more than 10hp anyhow, and it'd be squirrely with that. Go fishing.

If you buy a bigger boat, sell your 7.5 along with the jon boat. Combos are lots easier to sell. Get an outboard that hits the max for whatever boat you buy and enjoy what you have.

Life's too short and there isn't enough time in it to worry about another couple of MPH.

 

[steelespike]

Re: more speed out of 54 evinrude 7.5hp

i get going right at 15mph....and i have the wrong prop...i only have a 2 blade prop...my 12ft jon boat only weighs 80lbs or so. i have to sit in just the right spot...right behind my middle seat...and that gives me the best speed. so everyone on here says i should be using a 24:1 mix....and all the boat shops say 50:1 with the oils in current day gasoline...i have only ran 24:1 would it get more speed using 50:1?

Motor came with a 8" X 8 1/2" 2 bld. prop.You might try raising the motor starting with the antiventilation plate even with the bottom of the boat raise it 1/4 inch at a time until it ventilates or stops pumping water.If its really deep now you could gain a mph or more.
Originally rated at 16:1, 24:1 with TCW3 rated oil is ok.
Motor is all friction bearings and won't tollerate less oil.

 

[wbeaton]

Re: more speed out of 54 evinrude 7.5hp

This is a little old, but I just saw this post now...

That motor was only rated to get 17 mph new so I think you are lucky to get 15 mph. I only get 10-11 mph out of my 7.5's.

Now I have to find the video of your boat. Do you have a link?

 

[wbeaton]

Re: more speed out of 54 evinrude 7.5hp

Nevermind. I found the video. You're getting 15 mph with two people? That's great. Quit complaining and enjoy the ride