# Jack plate setback?



## stxhunter (May 19, 2006)

What is the advantage to having more setback on your jack plate? Does it allow you to move your motor up evein more? Even with my jackplate all the way up I have had no real problems with cavitation.


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## bboswell (Aug 14, 2006)

Yes, but it also creates more stress on your transom.

So I would like to add to your question...Is there such a thing as too much set back?


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## CoastalOutfitters (Aug 20, 2004)

as your motor moves back to meet the column of water exiting behind your hull you can run your motor in that elevated column of water...............to a point...........
less motor in the water , less drag, more speed

it has to be clean un-aerated water.............not like jon boats typically throw

2 big downsides ......

boat spinout in a turn

backing up

and yes transom stress , it is a simple effect of adding leverage force


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## thundertrout (Jun 22, 2006)

let me add a question to your question.would it be worth the xpence to have a set back on a tunnel hull on a majek it already has cmc j/p?


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## dennis_99 (Feb 27, 2006)

Interesting thread.


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## lbredfish (Apr 18, 2008)

The theory has always been for every 1" of set-back you could go up 3/8". I did it with a tunnel boat and adding transom shims helped alot mainly shallow take-offs


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## Dookie Ray (Apr 9, 2008)

I run a Marshall Flats with no tunnel and a set back plate and a jack plate. My motor sits 12.5" off the transom. Norman builds his boats with the extra reinforcement in the transom to handle the motor hanging that far off it. I've seen his "Topwater" with the same set up. The back end of my boat is has the transom totally encased with supports running through the deck to the stringers. I can run much shallower than expected, but if I have my motor up too high, the prop blows out. I guess what I'm saying is, you can run shallower, but from what I've seen, I wouldn't set my motor too far back on any boat except for the ones that are designed and built to take it. Just my 2 cents, hope it helps.


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## stxhunter (May 19, 2006)

I saw a 2" setback for a CMC jack plate, is this enough? Also will I still have decent "grip" in the water with my engine lifted with the set back?


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## spitfire (Jan 2, 2007)

I have a question. How do I get more speed using my jack plate?


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## fishrmn27 (Mar 23, 2008)

*Jack Plate.*



spitfire said:


> I have a question. How do I get more speed using my jack plate?


Once you get trimmed out and are running all out, start to come up with the jack plate. You will feel a speed change. Once the speed change goes the other way you need to stop and reposition to the fastest speed. Make sure and *watch your water pressure*. You can come up too far and minimize your water pressure causing problems you would rather not deal with!


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## bboswell (Aug 14, 2006)

stxhunter said:


> I saw a 2" setback for a CMC jack plate, is this enough? Also will I still have decent "grip" in the water with my engine lifted with the set back?


I noticed that Bob's makes Jack plates with various set backs of up to 10"


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## Spots and Dots (May 23, 2004)

Dookie Ray said:


> I run a Marshall Flats with no tunnel and a set back plate and a jack plate. My motor sits 12.5" off the transom. Norman builds his boats with the extra reinforcement in the transom to handle the motor hanging that far off it. I've seen his "Topwater" with the same set up. The back end of my boat is has the transom totally encased with supports running through the deck to the stringers. I can run much shallower than expected, but if I have my motor up too high, the prop blows out. I guess what I'm saying is, you can run shallower, but from what I've seen, I wouldn't set my motor too far back on any boat except for the ones that are designed and built to take it. Just my 2 cents, hope it helps.


Dookie is right. We run a Topwater, with a CMC and a Flats jack. Everything he said is true, and the boats are built for that set up.


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