# 4" or 6" Jack Plate



## Jared T. (Apr 13, 2014)

I am at a crossroads as to which to get. What are the pros and cons versus 4" and 6"? Will I get cleaner water further back? Can I run my motor higher with it further back? With it back further how will it affect the squat? It will be going on a Johnsen skiff with sponsens.


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## yobata (Jul 14, 2015)

I haven't seen any new photos of your boat, please post some. Always thought it was very cool that you were able to add sponsons!


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## Smackdaddy53 (Dec 31, 2012)

It all depends on the boat and motor plus other factors. There is a balance you need to meet to make the combination function at maximum efficiency. Too far back (more setback) and you create a lever effect and the stern squats more at rest BUT you get the prop where the water column rises off the hull at a higher point depending on weight distribution. Closer to the transom (less setback) keeps more weight forward and you jump on plane quicker as long as you aren't stern heavy. It has to be balanced and you can't get it right by guessing, only by testing the attitude of your weight distribution which changes your water column which changes where your prop needs to be to pick the water up without cavitating and create propulsion.


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## Capnredfish (Feb 1, 2012)

I would go with the 4. It's not a speed boat. But being a skiff you want less squat. Bad enough having to add the weight of JP. All this balancing will most likely require adding weight which will hurt speed. Nothing to move on my skiff. Tank is already up front. Maybe you can move things on yours.


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## Jared T. (Apr 13, 2014)

The gas tank, ~18 gallons, will be upfront with batteries. Technically the jack plate would 5.5" back. I think I will gain more by the 1.5" than the squat especially since I'm a tiny guy, 165lbs.


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## devrep (Feb 22, 2009)

On a skiff that size 4".


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## firecat1981 (Nov 27, 2007)

2" isn't going to get you into any significantly cleaner water. For example when Armstrong brackets does it's math they figure on .75" of water rise per 1ft of set back. So you would only get maybe another 1/8" to run the motor higher, but moving the heaviest static piece of equipment back a few inches will effect balance and draft.


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## No Bait / Lures Only (Apr 10, 2011)

I went with a Vance 4" on my Spear Glade X, did not get enough height an then added a 1/2" aluminum plate riser n 5/4" teak spacer. Then gained enough height to run my motor at peak rpm's.


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