How I built a "Jack Plate"

Discussion in 'Bubba's Outboards' started by Bobpaul, Mar 3, 2006.

  1. Bobpaul

    Bobpaul New Member

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    This is the first set of pics.

    Material used was 3x3 aluminum angle, s/s 1/2" nuts and bolts, and 3/4 plywood. 3 pieces of plywood laminated together to equal a thickness of 2 1/4".

    Tools used were, a circular saw, drill, a tape measure, and a small drill press. Being able to read a tape measure and getting lucky helps too.

    This was built on the tail gate of my p/u truck.
     

    Attached Files:

  2. Bobpaul

    Bobpaul New Member

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    I mounted a 25 hp merc on my boat and saw that the anti cav plate was about 3" below the hull, so I offset the aluminum angle that distance.

    I could've offset it more to raise the motor a bit more because the motor will be set back 3" also. That being because water comes up from under your boat as it moves forward.

    Take notice of high power bass boats with adjustable or hydrolic adjustable jack plates. Their set back allows for the motor to be raised quite a bit to eliminate drag. Some even go to the expense of specially made lower units with a forward bottom water pick up, made by Bob's Machine shop in Fl, no relation.

    Now for some more pics, of my version.
     

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  3. Bobpaul

    Bobpaul New Member

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    The boat is a 16' Landau with foot controlled trolling motor, a battery in front for it, extended casting deck, a 6 gallon tank and with all the other equipment and myself with my friend Cat Tale (Mike Hardee), it will run better than 30 mph.

    Notice that I had just enough clearance for the mounting screws on the engine to clamp the motor to it. That's where the luck came in. I also through bolted it at the bottom of the engine mounting bracket to the jack plate.
     

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  4. Bobpaul

    Bobpaul New Member

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    And here's a pic of the whole boat.

    Ya'll gonna have to waite if you want measurements of all this, cause I forget what they all were. I've built a few and all except the plywood thickness were slightly different to suit the boat. Yeah, custom made.
     

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  5. Bubbakat

    Bubbakat New Member

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    4,532
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    Now Robert that is what I call southern engineering.:)

    Wonder if that would work on my little 12 footer.:p
     
  6. Bobpaul

    Bobpaul New Member

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    Well Bubba, give it a try and get that 12'r up to about 20 mph and scare hell outta yo' self
     
  7. sliprig1

    sliprig1 New Member

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    Sweet, my boat could use one of those.

    Slip
     
  8. bigfish

    bigfish New Member

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    hey bobpaul have a couple ? for ya. well first what is the red and white contraption at the bottom of your boat. second noticed you have a tiller extension on : i was looking at them tonight online, and they say you should only use at trolling speeds. do you use yours when running full speed? is it safe and do you like it. the bench seat is a little to far up for me to realy stear comfortably, as i am only 5'6 need some way to get tiller out to me since i cant get my arm to grow anymore. and thanks so much for posting the jack plate. i havent checked mine yet, but im sure it sits to low.
     
  9. beeheck

    beeheck New Member

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    Good post, that leaves nothing to imagination, just what I need.
     
  10. Cat Tale

    Cat Tale New Member

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    The red and white deal on the back of Bobs boat is a bilge pump for his live well.He uses that extension at speed also.That boat will scat too.I've been with him quite a few times and it doesnt take long at all to get to the hole.
    I built a riser for my motor,it's a 12ft with a 9.9,and it will scare the S out of you at speed.She was real twitchy until I added a hydrofoil.Now it's very quick to plane off and more stable feeling.
     
  11. Bobpaul

    Bobpaul New Member

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    The red and white cantraption is a live well pump, plumbed to the front.

    The tiller extention is from minkota and not for high hp engines. It's designed as an extention for trolling motors and nothing over a 25 outboard. It can come loose, and has if your not careful. I need to put a bit of caulking inside where it attaches and a large hose clamp on it.

    My bench seat is like yours. A little too far forward, even without the jack plate.

    And yes I use it at full throttle, but I've been known to do crazy things. It's all in getting to know your equipment.
     
  12. Matt Smith

    Matt Smith New Member

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    Thanks BobPaul! This needs to go in the library. I have one question, though. What thickness is the angle? Will 1/4" work or is 3/8" necessary?
     
  13. Bobpaul

    Bobpaul New Member

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    Sure 1/4" should be fine and Whistler put it in the library last night. All on one page with bigger visible pics, no click'n on links there.

    I'll go out and take the measurement later and get them posted too.
     
  14. Dave53

    Dave53 New Member

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    Bobpaul,,,I'm going to act as though I do not know what a Jack plate does and that seems easy for me to do because I really dont! Is it for more speed?
     
  15. Bobpaul

    Bobpaul New Member

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    It's for getting your engine up to the right elevation relating to your hull.

    If your transom's for a 15" motor and you've got a 20" motor, get or build a jack plate to get your motor up 5" and run more efficiently, which will usually result in more speed.
     
  16. Bubbakat

    Bubbakat New Member

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    4,532
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    Bob I took your idea this last weekend and built me a plate to mount my long shaft suzki on my 12 foot tinney.
    Real stout and the motor runs so good and has had very little use so i used your idea and will water test it this week end.

    Looks a little funny but is workable:p
     
  17. Bobpaul

    Bobpaul New Member

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    We'll be looking forwardto the pics and results. Wear your life jacket and helmet.;)
     
  18. Dave53

    Dave53 New Member

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    Lonedell M
    Bobpaul, I noticed from your pictures that your motor seems to be sitting straight up and down back from your transit..I went out and looked at mine and it sits more of an angle with the transit?? Should I move the motor out so it sits like yours?? This is clear in my mind but I'm not sure if I have explained it correctly:confused:
     
  19. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
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    Yea set that thing straight up and down. I run mine a little tilted in when taking off to get that out of the hole shot I like sometimes.
     
  20. Bobpaul

    Bobpaul New Member

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    I've found on most motors I've mounted that the best performance position is in the second hole up.

    It's a trial and error thing, depending on your boat weight with load on it. Length and weight distribution play a big part in the motor's position, along with the available hp.

    What I try to get is the position that let's the motor excellorate easily, and run at max rpm's when I want it to.

    When on plane, your motor is lifting your whole boat up by the transom, while pushing it forward.

    I had a 9.9 Johnson on that 16' Landau first. It lugged getting it to plane, but by adding a dolphin hydrofoil to the anti cavitaion plate, it planed out quicker.

    You can only do so much. If your bow rides high, lower the motor position, or raise it if the bow plows through the water.