# Mini Jack plate worth it?



## chavist93 (Oct 1, 2010)

I have a Mercury 9.9 2 stroke on my 12' Lowe jon. The anit cavitation plate is now aroud 1.5"-2" below the bottom of the boat and the only way to raise it would be a mini jack plate. I have a hydrofoil on to help with planing and its below the surface of the water at speed so I may be losing a considerable amount of top end due to drag. Would the gains from raising the engine be worth the $100 cost of the jack plate?


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## lckstckn2smknbrls (Oct 1, 2010)

Try putting apiece of 1" thick wood on top of the transom as long as you can safely mount the motor.


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## Bubba (Oct 1, 2010)

I would try to find a cheaper way to raise it up if at all possible first. You would see very little(if any) benefit from the setback of a jackplate, so all you really need to do is raise it. So I assume you've already got it slid up the motor mount slides as far as possible already?(Or does your motor even have the bolt hold "slides"?)


Edit* Nevermind, I forgot that small of a motor probably just has the clamp-on type mounts.


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## chavist93 (Oct 2, 2010)

Yes the clamps are already as high as they can safley go on the transom.


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## clarkbre (Oct 2, 2010)

What kind/size boat is this on?

I don't know if you'd gain much by raising it an inch or two but you might try just taking the hydrofoil off. It may perk up with less drag in the water.

However, if the motor is on the small side for your boat, there is nothing that will substitute for more hp.


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## chavist93 (Oct 3, 2010)

Clarkebre, the boat is a 12'/36" wide Lowe flat bottom jon. It's not underpowered, max hp on the boat is 10hp. I'm not complaining about the speed, it's plenty fast as it is. The hydrofoil actually gained a little speed, and makes the boat plane off almost instantly so it's going to stay on.


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## clarkbre (Oct 3, 2010)

chavist93 said:


> I have a hydrofoil on to help with planing and its below the surface of the water at speed so I may be losing a considerable amount of top end due to drag.





chavist93 said:


> The hydrofoil actually gained a little speed, and makes the boat plane off almost instantly so it's going to stay on.



So what exactly is the issue? 

If it ain’t broke…Don’t fix it!


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## Quackrstackr (Oct 3, 2010)

clarkbre said:


> chavist93 said:
> 
> 
> > I have a hydrofoil on to help with planing and its below the surface of the water at speed so I may be losing a considerable amount of top end due to drag.
> ...



Exactly what I was thinking. 

The hydrofoil is supposed to stay below the surface while at speed.


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## chavist93 (Oct 3, 2010)

In an email replay directly from the hydrofoil manufacture (stingray), I was informed that the hydrofoild should be at the surface to no more than one inch below when on plane.


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## Alumacraft (Oct 3, 2010)

I have a 1236 lund jon boat, the exact same as your lowe, and I have a 9.9 Evinrude.

Im in the same situation. I was thinking of getting a mini jack plate because my cavition plate is 2" below the boat.

the river I fish is very shallow in the summer, that is why I would want to buy the mini jack plate, I dont think the speed would change though?


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## Alumacraft (Oct 3, 2010)




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## chavist93 (Oct 4, 2010)

Alumacraft, mine is pretty much the same, maybe a tad higher. Does the 9.9 have any problem planing for you or do you have any issues kepping the bow down at low speeds? I am a heavy guy, around 240lbs. plus 6 gallon tank, battery, and fishing gear there was too much weight in the rear to keep the bow down. The hydrofoil pretty much eliminated those problems. I may just try the mini jack plate if only for the advantage in shallow water wich is pretty much what I will use it for. I'll be sure to post the results. Now which to go with, T&H marine or Bob's Machine?


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## lckstckn2smknbrls (Oct 4, 2010)

For every inch of set back you can raise the motor 1/4 inch as long as the water pick up is still below the water level. The TH mini jacker has 4 inches of set back. I ended up with the motor 2" higher than the bottom of the hull.


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## Pappy (Oct 4, 2010)

You can be more aggressive than that with a jack plate on a small boat. With your set up you may possibly be able to raise the engine as much as 1.5 - 2" above the bottom. That is the measurement taken with the cavitation plate parallel to the bottom of the boat (not trimmed down) meaning that the plate is at the same angle as the boat bottom when you do your measurement and make a height change. You will find a little more speed due to the reduction in parasitic drag plus the Stingray will be out of the water up on plane where it is not normally needed. Take a look at this forum and do a search for jack plates or set back plates and read what these folks are doing. Their boats are small, light and not normally performance oriented but some of the guys in there are making them fly. With the hard chines of the aluminum boat vs. the rounded chines of the boats in the link you may experience better results than they typically do.
https://www.customgheenoe.com/forum/viewforum.php?f=5&sid=449e2413cb14aaea6f7d0e1c810444dd
Small engines and small boats can see benefits of both set back and raised engine heights. The boat manufacturers of the typicall aluminum boats are usually way on the conservative side on set up.


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## Alumacraft (Oct 6, 2010)

Im 150 lbs I plane out very easily. trolling motor up front, 3 gallon gas tank behind the middle seat. Its pretty fast with just me in the boat.

boat 140 lbs
9.9 evinrude 80 lbs
me 150 lbs
TM, battery, gas, gear 80 lbs

its only around 450 lbs the 9.9 has to push around. 

I can go way faster than my bros 12 mirro caft with a 9.9 evinrude :twisted: :twisted: 

Late winter early spring I'll be putting in a 3/8" floor for the middle and front of the boat and then I'll look for a small jack plate for my boat. I'll probly put the cavitation plate .5" or 1" above the bottom of the boat, but I'll have to play around with it.


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