I have a 14' jon boat with a 36volt golf cart motor mounted to a 1959 5.5hp evinrude lower unit. It functions fine ,but is not fast enough. I'd like to step up to a 48 volt motor. My ? is if I just replace the 36v with the 48v am I going to get max benefit/efficiency or would I be better served getting a newer lower unit. The 5.5 has a 2 blade prop. with no interchanges. I'm thinking if I went with a newer lower unit there would more prop options and I might see a benefit in a prop change. I live in MD. is there a shop/person that builds/works on this style electric motor set-up. My understanding is this set-up pre-dates the commercial electric motors that are popular and $5k. thanks Paul

You gotta a picture of that motor?  I'd love to see that setup.  

here's a picture. I had to size it it looks stretched

NOW THAT IS SOME ENGINEERING!!!! AWESOME, TRULY AWESOM!!!!!!!

That motor is so awesome!!!  Its by far the coolest electric I have ever seen!!!

Tinkerer,

Sorry that I can't answer your question but that is one sweet motor.  How long have you had it?  How much thrust/hp do you estimate that you have?  Was it made by someone who sells them?  I am asking all this because I am in MD also and always looking for more power on our electric lakes.

Thanks

Hey Steve,

I purchased the boat, motor and trailer last year from a local man. He purchased it approx. 10yrs earlier from another local, they both fished it in Liberty.

The man I bought it from owned a plumbing business and most recently(5-7 yrs ago) used it to install water pipes under the piers in the inner harbor. I don't know the thrust rating, tag on the motor rates the hp at 1.5. Although it moves the boat well, I'm not impressed and I'm looking to improve it. I found a co. in N.Y that I can buy a new electric motor rated at around 5hp. The representative said they could make additional modifications if it still wasn't fast enough. The down side is the faster you go the more amps you draw which translates into more batteries. I'm considering picking up another lower unit and building a entirely new motor with some different prop options.

PS The appearance of the boat, motor and trailer now do not remotely resemble the condition when I purchased them. The boat was typical goose sh** green.

Paul

Thanks for the reply.  Yep, you really need a lot of batteries on a lake the size of Liberty.  Hope your search for more power works out.

Steve

Tinkerr, somehow I missed your post?

Changing up to a larger prop should prove to be faster in your circumstance. Your best bet would be to run a 9.9 lower unit. They can be hard to find around here especially at a reasonable cost. You need to remember that a the best Electric powered outboards run a big prop turned at relatively lower rpms. (lower then the gas motor you are discarding) This will give you the best speed while still maintaining a reasonable amp draw / runtime. In just about all situations, the faster you go the more you will pay. This is true for not only the money spent, but in your runtimes as well. So keep that in mind when your making changes.

Are you running solenoids to control the motors speed or a PWM (pulse width modulation) controller?

If you can find one (?) the new 9.9 Yamaha High torque lower unit would serve you perfectly. It's now the electric motor builders lower unit of choice. It's gearing and prop is much better suited for this application, and it's not available with either a merc or johnson.

Striperone,

I'm using a solenoid set-up at 24 and 36volts. Doing some investigating I have found a 3 blade prop. available for the current lower unit. The cost is about a $100, but I'm hesitant to spend that not knowing if I'll see a noticeable increase in speed. The 9.9 Yamaha sounds interesting, but I'm thinking it's going to be cost prohibitive, trying to improve with minimal expense. The new electric motor is $625+shipping. Add to that all of the unforeseen expenses and I'll be at $800. I'll keep my eye out for that 9.9 Yamaha. Is there a benefit using a standard 9.9 over a 7.5 or 8hp?  Thanks for the replies

Tinkerr,

  I have built and rebuilt several of these motors for my boat.  You have to be carefull when swithing motors that the outpot shaft and couplers you have are the same size, or you will be out trying to find the correct size.  Where in MD are you I have the lower unit off of an 80 hp merc you can have if you want to come get it.  I was going to try and mount my motor to it but found the motor housing had split due to water intrusion and freezing.   I found a good deal on a pair of minn kotas that I use now.  The best thing is i can talk to the person in the boat with me while I am running.  The golf cart motor are nice but unless you want to buy a RAY motor you are not going to find them very efficient.    Do a google search for Ray electric motor they have good info on their site.

TD

Tinkerr, Running a 9.9 just allows you to run a bigger prop. You said you have bought a new motor. What horsepower and who is it make by? Another thing you should consider is changing out those old solenoids for a pulse width speed controller. You will not only extend your run time but will have a full variable speed capabilities as well. No more jerky take offs or speed changes either.

Standard lower horse powered outboards use either a 1.7:1 or 2.0:1 gear ratio. The newer Yamaha High torque motor uses 2.9:1. Remember that efficiently is gained dramatically by running a relatively big prop at lower speeds.

As TD has pointed out you may have to change your "love joy connectors" to match any spline or diameter differences between the motor and the lower unit shaft. If you live in Maryland, Grainger has them. You can buy them individually or in pairs.

 

It is also built on the Yamaha's lower unit. I have a Ray Electric Outboard after many years of building my own. This one has some good specs, but it's not yet proven in longevity or maintenance free as with the Ray's.

Scottie Too Hottie

Snapperd1,

Thanks for the offer on the 80hp. I'm thinking it would be to large. Dragging the extra weight and turning that large lower unit is going to impact efficiency.  I've got the coupling's covered. The wife's uncle is a suit at a coupling manufacturer in MD. He supplied the one in the picture and the price was right FREE.

Stripperone,

I haven't purchased the new motor, I'm still weighing my options, The motor is from a Co. in N.Y. D&D electric motors. They specialize in golf cart motors, they have and will build motors for custom applications. The motor that was recommended is a 5hp and was told it would operate at about 120amps.

I got a price on a three blade prop. for the current set-up $79. Thinking about changing the prop. ,maybe the solenoids, then evaluate the results, meanwhile keeping a lookout for a 9.9hp lower unit to put together a new motor combo.

I've seen Ray's electric motors, the expense it a little much for me to justify. With 5-6k I could finish my car or rework my pond.

Scottie- What is the pricetag on that motor on your site?  It wouldn't load in full size for me.  Thanks

Low_Budget_Hookers,

The motor is very pricey. Their fastest motor cost around $7000.00 NOT including batteries. It also draws 130amps. It has some very unique features to it like a water cooled motor and controller.

I have had the opportunity to ride in a boat powered by this motor and I can say first hand, "its fast"

In comparing it to a RAY, there are advantages and disadvantages. A Ray draws 80amps, compared to 130 (both a full tilt boogie) A Ray cost 5300.00 compared to 7000.00. (neither include batteries, an additional 800.00) The reservoir motor includes a factory Yamaha trim and tilt, the Ray does not.

The Ray motor produces 270 lbs of thrust. The Reservoir motor does not advertise it's thrust, but I can tell you it is FASTER.

Neither of these motors are for everyone. But if you run electric motor only reservoirs, they are a MUST HAVE.

great topic

lotsa info here!

thanks