# Manual jack plate on a ShadowCast 16



## Fishtex (May 10, 2014)

I spoke with Ankona and they did not recommend jack plates on the Shadowcast. However it doesn’t mean it cannot be improved, It may be a situation of proper prop and the right jack plate combo/height, plus a compression plate. Meaning the factory situation is just fine, runs shallow, no need for the expense of a jack plate or custom prop. But it is still possible to improve the running draft, hole shot if you are willing to go that far....is it worth it for a few inches? Go to an expert like Jack Foreman at Crossroads Propeller service and discuss. In my view the obsession with shallow running gets to be pissing contest at some point. It can lead you to running places where you should be poling...I have two props on my workbench.......


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## trekker (Sep 19, 2015)

Do it.


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## Backcountry 16 (Mar 15, 2016)

I had a shadowcast and that thing easily ran in 4 inches how shallow are you running in yours?


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## Guest (Dec 1, 2018)

Post some pics of your set up. Maybe we will notice something that can be tweaked.


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## Capnredfish (Feb 1, 2012)

Backcountry 16 said:


> I had a shadowcast and that thing easily ran in 4 inches how shallow are you running in yours?


I question this.
From Ankona, positioning the propeller shaft just above the hull bottom for very shallow running. So to run in less than 4 inches you must have prop less than 8 inches in diameter and hull can not be in the water along with a trimmed off skeg. Magic carpet? Did you have a jackplate to raise skeg to bottom of hull? Because any moving skiff still sits in the water.


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## Backcountry 16 (Mar 15, 2016)

Capnredfish said:


> I question this.
> From Ankona, positioning the propeller shaft just above the hull bottom for very shallow running. So to run in less than 4 inches you must have prop less than 8 inches in diameter and hull can not be in the water along with a trimmed off skeg. Magic carpet? Did you have a jackplate to raise skeg to bottom of hull? Because any moving skiff still sits in the water.


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## Capnredfish (Feb 1, 2012)

From that pic looks like it won’t run in twelve inches.


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## Backcountry 16 (Mar 15, 2016)

Capnredfish said:


> From that pic looks like it won’t run in twelve inches.


Pics are deceiving once the boat is on plane it funnels the water back to the motor and it will run super shallow. I dontd own rge boat anymore it wss a little to tippy for my Dad. Bought a spear best move I've made.


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## Capnredfish (Feb 1, 2012)

I always question draft claims like that. Skiffs don’t ride above water so there is draft right there. Add what ever hangs below hull such as prop and skeg, usually skeg.


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## Backcountry 16 (Mar 15, 2016)

Capnredfish said:


> I always question draft claims like that. Skiffs don’t ride above water so there is draft right there. Add what ever hangs below hull such as prop and skeg, usually skeg.


Maybe ankona would be better to talk to about it I'm just telling you my experience running past half exposed crab traps.


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## Travisloyd07 (Jan 31, 2014)

@Capnredfish


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## Guest (Dec 1, 2018)

Tough to say for sure from the pics, But I am willing to bet that motor can come up quite a bit!


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## rickc (Nov 7, 2018)

rule of thumb is cavitation plate even with the top of that tunnel. my experience is you can easily go 1 to 2 inches higher. with a manual jackplate with the setback certainly higher. with one of these http://stiffypushpoles.com/shawwing-cavitation-plates certainly higher.

get the lightest manual jackplate you can find. here is a link for a bobs mini manual. https://bobsmachine.com/product/mini-manual-jack-plate-mmj-0-40-hp-max-for-clamp-on-motors/

then experiement. a water pressure gauge would be a good idea. you will probably need a 4 blade with lots of cup but that is another experiment.


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## Capnredfish (Feb 1, 2012)

Now we have something to go by. But unless that boat is above the water, it’s not running in 4 inches. Shallow, yes. Maybe I’m wrong. Just don’t see how.
Hold a 2X4(3 3/4”)even with the bottom of the skeg. That’s close to the 4” claim. If whatever is left between the top of 2x4 and bottom of hull is all air when running I’m buying one.


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## Guest (Dec 1, 2018)

Capnredfish said:


> Now we have something to go by. But unless that boat is above the water, it’s not running in 4 inches. Shallow, yes. Maybe I’m wrong. Just don’t see how.
> Hold a 2X4(3 3/4”)even with the bottom of the skeg. That’s close to the 4” claim. If whatever is left between the top of 2x4 and bottom of hull is all air when running I’m buying one.


Just give me some time! Let me get hull #1 completed and I’ll put the tunnel in #2. Unless my customer wants a tunnel and is willing to give me a little extra time to tune it in to this hull!


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## Smackdaddy53 (Dec 31, 2012)

rickc said:


> rule of thumb is cavitation plate even with the top of that tunnel. my experience is you can easily go 1 to 2 inches higher. with a manual jackplate with the setback certainly higher. with one of these http://stiffypushpoles.com/shawwing-cavitation-plates certainly higher.
> 
> get the lightest manual jackplate you can find. here is a link for a bobs mini manual. https://bobsmachine.com/product/mini-manual-jack-plate-mmj-0-40-hp-max-for-clamp-on-motors/
> 
> then experiement. a water pressure gauge would be a good idea. you will probably need a 4 blade with lots of cup but that is another experiment.


I’m not being rude, just stating a fact. I read and hear people saying a 4 blade prop is for running shallow and a 3 blade is for speed. This is a very common misconception...4 blade props are not always what an outboard needs to run the motor higher without blowing out. Depending on the setup a three blade with XXX cup will run way high and not lose grip in turns. At the same time on certain hull and motor setups a 4 blade prop will run faster than a 3 blade.


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## rickc (Nov 7, 2018)

Smackdaddy53 said:


> I’m not being rude, just stating a fact. I read and hear people saying a 4 blade prop is for running shallow and a 3 blade is for speed. This is a very common misconception...4 blade props are not always what an outboard needs to run the motor higher without blowing out. Depending on the setup a three blade with XXX cup will run way high and not lose grip in turns. At the same time on certain hull and motor setups a 4 blade prop will run faster than a 3 blade.


i won't disagree. spent a lot of money in search of the perfect pro in the past.

ankona has been there and done that. their advice is probably where you wind up.


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## Capnredfish (Feb 1, 2012)

I think that old misconception is based on off the shelf props. I do run a four blade. Then Forman came up with a better three blade, but I was already invested.


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## Guest (Dec 2, 2018)

Capnredfish said:


> I think that old misconception is based on off the shelf props. I do run a four blade. Then Forman came up with a better three blade, but I was already invested.


This is most likely the case in my experience at least.


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## Smackdaddy53 (Dec 31, 2012)

Capnredfish said:


> I think that old misconception is based on off the shelf props. I do run a four blade. Then Forman came up with a better three blade, but I was already invested.


I believed it as well but not anymore.


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## Backwater (Dec 14, 2014)

He can put the manual JP on and install a cavitation plate. Then adjust the JP up until the prop still bites good and not blowing out, while getting good force fed water to his lower water pickup. Then he can trim the motor up while he's running and overall reduce his running depth, as long as he's still getting good prop bite and the OB is still pissing like a race horse!


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## jlindsley (Nov 24, 2015)

Backcountry 16 said:


> I had a shadowcast and that thing easily ran in 4 inches how shallow are you running in yours?


4” Seagrass is coming out of the water. So if you easily ran in 4” of water when did you start touching bottom? 2”?


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## Capnredfish (Feb 1, 2012)

Doesn’t appear like we have made much headway in the super skinny running. This is from 56


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## GG34 (May 2, 2014)

I would recommend a manual jackplate with a hydraulic one as well. A Shaw wing with an 8 bladed prop, super cupped. Then use silicon bunk spray and you'll probably be about to run from your driveway to the flats. Just don't unhook your safety chain until you are ready to roll . Good luck.


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## Capnredfish (Feb 1, 2012)

Here is another pic. These are badass.


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

Travisloyd07 said:


> I have a Sahdowcast 16 with a tiller 20hp Yamaha 4S short shaft. I continue to find that it floats in less then it will run in. I was thinking of a manual jp so I can just set it and forget it. I’m sure it will take a bit of testing to get it at the right height. Is anyone running a jack plate on their’s?
> If so which one?
> Pro and cons on a tunnel?
> 
> ...


I have purchased 2 Vance manual jackplate two different boats. Spear Glades x n 18×60 uncle j flat. After fine tuning the elevation ur good to go..
By the way vance Jack plate have an adjustment bolt for ease to tune height..
The 30 hp version weight like 10# , 140 hp version 25#


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## Capnredfish (Feb 1, 2012)

I’ve never seen an outboard powered jet ski.


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## ZaneD (Feb 28, 2017)

I have a 16' Shadowcast with an F20, and I run a three blade prop. My skiff originally had an Atlas Micro-Jacker, which allowed me to raise the engine 2-3" while running before the prop blew out. For me this difference in draft was not important, so I decided to remove the JP to lose some weight and simplify things. Without it I can run in about 10-12" of water, if you install a JP and a cupped prop you could probably get down to running in 8" if you're lucky. 

So in short, I say that if losing a couple of inches of running draft is going to help you, go for it! But I am happy I got rid of mine.


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## Travisloyd07 (Jan 31, 2014)

ZaneD said:


> I have a 16' Shadowcast with an F20, and I run a three blade prop. My skiff originally had an Atlas Micro-Jacker, which allowed me to raise the engine 2-3" while running before the prop blew out. For me this difference in draft was not important, so I decided to remove the JP to lose some weight and simplify things. Without it I can run in about 10-12" of water, if you install a JP and a cupped prop you could probably get down to running in 8" if you're lucky.
> 
> So in short, I say that if losing a couple of inches of running draft is going to help you, go for it! But I am happy I got rid of mine.


Still have it? Want to sell it?


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## Dan8383 (Nov 22, 2018)

Maybe a gheenoe custom LT25 or shadowcast


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## Dan8383 (Nov 22, 2018)

Travisloyd07 said:


> Still have it? Want to sell it?[/QUOTE
> Have any pics on how high you can raise the jp before losing water pressure? thanms


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## Sublime (Oct 9, 2015)

My 07 Beavertail Bare Bones had a 50 etec mounted from the factory on a Vance manual plate. I would say 9”-12” running depth. Heck the prop was like what 12” in diameter so if you could run with the nose cone level with the bottom of the hull, you’re still going to have 6”-7” of prop and skeg below the hull.


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