Using Trolling Motor as an outboard

Discussion in 'Outboards' started by Stumble, Jul 6, 2009.

  1. BHOFM
    Joined: Jun 2008
    Posts: 457
    Likes: 14, Points: 0, Legacy Rep: 247
    Location: usa

    BHOFM Senior Member

    A place called Battery Outfitters, local company has over
    stock or slow movers that have been on the shelf and they
    discount the price. They call them Blems.

    Yes it is new, it has a two year replacement warranty.
    The label only says "Heavy Duty".

    I wanted a small, low profile and this just fit the bill.
    I thought if needed I could add a second one, but it
    seems fine with the one.
  2. BHOFM
    Joined: Jun 2008
    Posts: 457
    Likes: 14, Points: 0, Legacy Rep: 247
    Location: usa

    BHOFM Senior Member

    You are right, my bad. The label has been replaced so I
    don't really know all the spec's. I have been looking for
    a small V meter to take on the boat and get some info
    for people.
  3. Stumble
    Joined: Oct 2008
    Posts: 1,896
    Likes: 71, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    After doing this, my recomendation would be to buy the largest 12V motor you can, even in a small boat. The reality is that this is at best a marginal option for limited use, and the larger engines give at least some options. The other thing to remember is that these engines will drain a 75 amp hour deep cycle battery down to 50% in 60-90 minutes. This is the threshold for deep cycle batteries, and leaves you no room for running instruments, lights, whatever before you start doing damage to the battery. Finally even a small battery + the trolling motor is going to likely weigh MORE than just a small outboard+gas. So the only advantage in weight is the ability to multi-purpose the battery for more than just lights and electronics.

    Like I said I love the system and it works ok for me, but my needs are very limited, and I still have the gas engine at the dock for when I need it.
  4. BHOFM
    Joined: Jun 2008
    Posts: 457
    Likes: 14, Points: 0, Legacy Rep: 247
    Location: usa

    BHOFM Senior Member

    You have hit the nail square on the head.

    One more point, the battery takes up about the same
    amount of room as a 2 gallon gas can. Important on
    a small boat like mine. Also being able to place the
    battery at the best location for trim of the boat.

    On the lake, without tides and such it works very well.
    And at a much lower cost than an outboard.

    I have been using mine a little over a month, fifteen or
    so outings. I am 100% pleased, and if I had it to do over,
    every thing would be done the same.
  5. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 472, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The biggest 12 VDC is about 55 pounds of thrust or around 2/3's a HP.
  6. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    I have an empty jetski which I run with a 25 hp outbard ..but I bought the 86lb 24v trolling motor to put on so I can use it on the " electric only lakes" and wind up the patrol gastapo real bad ..I have enough trouble with the water police o a normal river who think its a jetsiki !!!
    Whilst the biggest 12 Minn Kota is 55lb I am not convinced they dont just run them on 24v and call them 80 lb !!!
  7. EddieWeeks
    Joined: Sep 2009
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Baton Rouge, Louisiana

    EddieWeeks Junior Member

    I have lots of experience with trolling motors on unmanned survey boats.

    Most trolling motor props have a pitch of around 4 inches. Once your up to speed, the prop slip is fairly low.. If I were you I would just run your 30lbs
    on 24 volts not full power at first. I don't think you will hurt it. Its water cooled it you will not run it for long... Its just a simple DC brushed motor.

    Here is a video of my boat with 2 x 30lbs running at 4.5 knots (12v)... 24 hours non stop.

    I also have made my own custom 6x9 inch props at one time..

    If you do try the 24 volts, your current will go up also and you power will go up more than 2x.. Your speed will not double though
    I think that is the best way to get 4 knots for 5min..

    Eddie Weeks
  8. robsail
    Joined: Dec 2011
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: California

    robsail New Member

    Very nice discussion on motor power for small sailboats. My 18 ft 600 pound sailing dinghy is regularly sailed in the ocean, and I have reluctantly concluded that I cannot rely on wind alone. The 7.5 ft beam and wide decks in the cockpit area would be a challenge for an oarsman. Electric is cool but -with recharging, battery weight etc, cost of batteries; a stinkmotor seems like the way to go--extra power and range.

    The honda 2 HP 4 cycle is light, reliable, but always reported to be noisy. In the under- 3PH category, very few motors out there with a 20 inch shaft. Any suggestions? R
  9. cyclops2
    Joined: Sep 2010
    Posts: 242
    Likes: 7, Points: 0, Legacy Rep: 94
    Location: New Jersy

    cyclops2 Senior Member

    Can you put a small guy in the cabin until it is needed ? Tank also somewhere.

    18' is draggy. You might like about 7 hp when the weather goes bad.
  10. cyclops2
    Joined: Sep 2010
    Posts: 242
    Likes: 7, Points: 0, Legacy Rep: 94
    Location: New Jersy

    cyclops2 Senior Member

    20" motor.

    I have a Evenrude electric start 9.9 that was easily converted from long to short as part of the purchase. Should be easy to do. I thought some motors made spacers to allow the length to be adjusted a little for the sail boats.
  11. Delane
    Joined: Apr 2005
    Posts: 91
    Likes: 4, Points: 0, Legacy Rep: 37
    Location: Okinawa, Japan

    Delane Senior Member

    Emergency Back Up

    I've thought of using one as an öh grap emergency propulsion. The idea was to install on the transom on a spring loaded swing down bracket that is rigged on a trip device with a full power on/off switch. If your engine quit suddenly in a precarious situation close to a reef or other boats, etc you could deploy it in about 2 seconds having control speed to the dock or to get you out of near danger until you could trouble shoot the primary motor or set anchor.
  12. Fanie
    Joined: Oct 2007
    Posts: 4,603
    Likes: 170, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    Trolling motors are essential if you fish, apart from that they can save the day. Just don't get too small a one. The bigger ones are so much better. They go over 130lb thrust nowadays.
  13. taniwha
    Joined: Sep 2003
    Posts: 205
    Likes: 9, Points: 18, Legacy Rep: 150
    Location: Pattaya, Thailand

    taniwha Senior Member

    make your life easy get yourself a Torqeedo, the battery is integrated and the GPS tells you how many miles you have left on the charge.
  14. keysdisease
    Joined: Mar 2006
    Posts: 794
    Likes: 43, Points: 28, Legacy Rep: 324
    Location: South Florida USA

    keysdisease Senior Member

    Torquedo is the hot setup, awesome power but VERY pricey. I iamgine you could by a good electric trolling motor, batteries and a 5hp gas outboard for when you need it and still be cheaper than a Torquedo.

    The nice thing about clamp on power is that you can change it easily. If you're just going from the mooring to the mouth of the harbor, electric. If you are going further and feel you may need more power or run time, gas (if allowed)

    Change out time = minutes

    Flexibility like this is really very cool.



  15. Submarine Tom

    Submarine Tom Previous Member

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.