Anyone ever tried trimming back a Bob's?

Discussion in 'Prop Shop' started by igoswoop, Jun 10, 2014.

  1. igoswoop

    igoswoop Well-Known Member

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    I've got a 15'4" NMZ that's had a 15 2stroke Yammi hanging on the transom since I got it. I've wanted this boat to run skinnier for awhile now and I've got to get this motor up higher to do it. Since I can't find a TomC jackplate anywhere, I'm thinking about getting a Bob's and trimming some material off and re drilling the mounting holes to reduce the set back. I really like the idea of having a little setback like Tom's design for the advantages a jackplate provides but I'm aware of the trade offs fiddling with my motor when it's further back stability-wise. I don't want my motor 4.25" back. I'd like about half that much so my idea was to remove about 1.25" of material from each half of the Bob's plate to bring the motor in closer. It won't be much, but it'll shave a little weight back there too. I've got access to a CNC mill to do the cuts, just not enough access to build my own jackplate from scratch.

    I'd almost settled up on just getting a riser plate but I do like the idea of being able to fine tune the perfect height I can go with the motor. This I can't do with a transom riser.

    I'm not adverse to installing a set of trim tabs to gain a little more lift too. I can source all the hardware to build a set for about $60.

    What do you think?
     
  2. MariettaMike

    MariettaMike Wish'n I was Fish'n!

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    bad idea. If you trim back the sides then there isn't room for the hydraulic cylinder, or space to access the mounting bolts.

    Atlas Micro Jacker is a better option. You won't notice the 4" setback, but you will be amazed at how much better your boat runs when you adjust the engine height for load, speed, and sea conditions.

    http://www.thmarine.com/products/Outboard-Jack-Plates/Hydraulic-Jack-Plates/ATLAS-hydraulic-jack-plates/Atlas-Micro-Jacker
     

  3. igoswoop

    igoswoop Well-Known Member

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    I'm not really concerned with clearance for a hydraulic cylinder; it's a manual jackplate??? There won't be one present to contend with the space.

    Seems like there'd be plenty of room to reach the hardware with a box end wrench on the inside and a ratchet on the outside. Maybe we aren't talking about the same jackplate? The Bob's Mini Manual jackplate is the one I'm referring to.

    http://www.bobsmachine.com/Mini-Manual-Jack-Plate-MMJ-0-40-HP-Max-Narrow-width-100-200500.htm

    Thanks for the link on the other one. I'll check it out.
     
  4. tomahawk

    tomahawk Well-Known Member

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  5. permitchaser

    permitchaser I Love Skinny Water

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    Why don't you put it on and try it before you start cutting. I thinks Bobs has worked out the perimeters of what it can do. I would also calls bobs and ask two questions. One, will this work on your boat and what to expect in performance and two if you cut it will it void your warranty

    Just say'en ;)
     
  6. goon squad

    goon squad I Love microskiff.com!

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    igoswoop, I sent you a PM
     
  7. igoswoop

    igoswoop Well-Known Member

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    permit - good call but I'm in no hope of retaining a warranty once I go hacking. I'm pretty sure I'm not interested in moving the motor that far back. My ideal product to purchase would be a TsG Slimline but the man's gotta fish so that isn't happening. =)

    goon - good stuff man. That's awesome.

    I'm gonna pass on the wood aspect of the dillon racing JP but I did pick up some 2"x2"x 1/4" angle aluminum today and a larger plate that was scrap. Looks like I'm gonna try to roll my own. With the price I paid for the aluminum plus another $20-$30 in stainless hardware, I can't justify the Bob's at this point.

    Pics to follow as I figure out whether I'm gonna mill a sliding track or just adjustment holes for the height. I kinda know the answer as to which I'd prefer to do but I suppose I can always just open up a channel between some holes for more adjustment. I've pretty much got nothing but time to kill while I wait for some more motor parts to come in so why not? Looks like I'm gonna build a hack job of what I like from all three designs.
     
  8. tomahawk

    tomahawk Well-Known Member

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    Swap the wood in the Dillon plans with starboard, although meranti marine ply encapsulated in epoxy is not rotting or going anywhere. Over drill the holes, fill with epoxy and then re drill. There will be no water intrusion. I'm using it because I have it, otherwise, I would probably go with starboard.
     
  9. State fish rob

    State fish rob Active Member

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    I used 3" x3/8 channel to raise 30 mariner on lowe jon boat. Easy job. All holes. No slots. Worked as expected