# T H Marine MJ1DP MINI JACK PLATE MINI-JACKER



## Flatsdaddy (Oct 24, 2010)

Has anyone used one of these? Is it adjustable for height? Does it work OK?


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## lckstckn2smknbrls (Oct 24, 2010)

I use one I'm very happy with it.
It is adjustable in that you can drill more holes in it to raise or lower it. For every inch of set back you can raise the motor 1/4"
I have it set so the anti-cavitation plate is about 1.5" to 2" above the bottom of the hull.


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## Flatsdaddy (Oct 24, 2010)

Thanks for the info, I see how it works now.

Looks like you have yours propped up a little with the piece of wood instead of moving the whole thing up a hole or 2.

A couple more questions if you have time:
Did you gain any speed or have any other large benefits besides being able to run shallower?
Is there enough room between the transom and the plate to screw the motor clamps to the jack plate?
Do you have your motor bolted to the plate?

Thanks again.


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## lckstckn2smknbrls (Oct 24, 2010)

Flatsdaddy said:


> Thanks for the info, I see how it works now.
> 
> Looks like you have yours propped up a little with the piece of wood instead of moving the whole thing up a hole or 2.
> 
> ...


I never GPS'd the speed before or after. Running shallow water was my main concern the motor is a short shaft but is a long short shaft. The wood was for testing I just never went back and raised the jack plate. No there is not enough room for the clamps they have to be above the transom. I haven't bolted the motor to the jack plate. 
I bought it new on ebay total cost with shipping was $42.00. The wood that comes with it was getting dented by the clamps so I added a piece of aluminum plate to it.


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## Flatsdaddy (Oct 24, 2010)

Bummer. They cost about twice that now.

With a standard short shaft motor, do you think I can I clamp the motor on the jack plate if I mount the plate even with the top of the transom (same height as yours)?

I would like the top of the plate to be even with the top of the transom and for the motor to sit down tight on the top of the plate. Do you think that will work?


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## lckstckn2smknbrls (Oct 25, 2010)

It should fit. 
If your motor is a standard short shaft and your transom is 15" why do you want a jack plate?


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## tccanoe (Oct 25, 2010)

The cavitation plate is the large plate just above the prop of the motor. This plate should be even with the bottom (keel) of the boat within an inch one way or the other. The idea of the Mini Jacker is to bring the cavitation plate in-line with the keel.


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## Flatsdaddy (Oct 25, 2010)

I got the motor jacked up about an inch off the top of the transom (like you have a board on your jack plate) and the cav plate is about an inch below the bottom of the boat.

I should be able to raise my motor 2.5 - 3 inches with a 6" setback jack plate. I would think that would translate into a little more speed as well as shallower running.


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## mhinkle1990 (Oct 25, 2010)

Im interested in putting a jack plate on my 14 foot 87 grumman. I have a 25hp 2 stroke mercury 2003 short shaft 15inch and i feel that when i run full throttle the back of the boat lifts up out of the water and pushes the bow down into the water creating a lot of draft. i figure that if i lift the motor out of the water more than it would prevent the bow from being driven into the water as much creating less draft. if i tilt the motor up and i run full throttle it is too dangerous and not easy to controll, it honestly feels like im running on 3 inches of the back of the boat and accelerating the bow is in the air way too much untill plane. i also was thinking about trim tabs....i know dont criticize but it actually would help tremendously! please give me input im new to the site and trying to get my johnny up to par!


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## lckstckn2smknbrls (Oct 26, 2010)

Flatsdaddy said:


> I got the motor jacked up about an inch off the top of the transom (like you have a board on your jack plate) and the cav plate is about an inch below the bottom of the boat.
> 
> I should be able to raise my motor 2.5 - 3 inches with a 6" setback jack plate. I would think that would translate into a little more speed as well as shallower running.


For 6" setback you could build my own several of the guys here have. Hunt around for some big aluminum angle or you might get lucky on ebay or craigs list.


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## lckstckn2smknbrls (Oct 26, 2010)

mhinkle1990 said:


> Im interested in putting a jack plate on my 14 foot 87 grumman. I have a 25hp 2 stroke mercury 2003 short shaft 15inch and i feel that when i run full throttle the back of the boat lifts up out of the water and pushes the bow down into the water creating a lot of draft. i figure that if i lift the motor out of the water more than it would prevent the bow from being driven into the water as much creating less draft. if i tilt the motor up and i run full throttle it is too dangerous and not easy to controll, it honestly feels like im running on 3 inches of the back of the boat and accelerating the bow is in the air way too much untill plane. i also was thinking about trim tabs....i know dont criticize but it actually would help tremendously! please give me input im new to the site and trying to get my johnny up to par!


You might look at mounting a hydrofoil on your motor.


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## tccanoe (Oct 26, 2010)

Ditto on the hydrofoil and you may also want to look at weight distrabution. Can you move your battery all the way foward? If your cavitation plate is close to even with the keel then I would not worry about the Mini Jacker. So lets get this stright. When the motor is trimed down you get better control out of the hole (good) but your bow gets pushed down into the water on plane (bad). Trim up and your bow points toward the sky (bad) out of the hole but the boat runs level on plane (good). This is a trim, motor and boat matching problem not a shaft length problem. Put a hydrafoil on your cavitation plate and keep the motor trimmed up. You should be good to go.


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## tccanoe (Oct 26, 2010)

tccanoe said:


> Ditto on the hydrofoil and you may also want to look at weight distrabution. Can you move your battery all the way foward?


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## Flatsdaddy (Oct 26, 2010)

lckstckn2smknbrls said:


> Flatsdaddy said:
> 
> 
> > I got the motor jacked up about an inch off the top of the transom (like you have a board on your jack plate) and the cav plate is about an inch below the bottom of the boat.
> ...




I have looked for used ones with no luck. I have priced material and by the time you figure labor (unless you luck up on scrap) it's cheaper to buy than build. I'd love to find a manually adjustable one to try out.

I may just wait until it gets too cold to fish to do anything.


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## mhinkle1990 (Oct 27, 2010)

yea whenever i have the motor trimmed down its awesome out of the whole but then the bow is pushed into the water....the opposite when trimmed up except it seems that it gets a little unstable when reaching top speed around 31-32mph on gps. whats the price range i should be looking for a hydrafoil for my specific motor/boat? after figuring this out my next task is re-painting my johnny. is it better to do with cans? whats more cost effective? im a college student paying for school/rent/car/ and every other expense you can imagine working full time and going to school full time. i love my jon, it helps me free my mind every chance i get but can only improve it with cheap and cost effective improvements. Any advice helps!!!! the preferred coloro would be a darker blue or maybe a camo but everyone does that....dont want nothing to flashy either! 8)


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## tccanoe (Oct 27, 2010)

Hink, Doil-Fin at Boaters World is 41 bucks that includes shipping.


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## mhinkle1990 (Oct 27, 2010)

tccanoe said:


> Hink, Doil-Fin at Boaters World is 41 bucks that includes shipping.



thank tc, i just checked it out and im going to place the order this friday! installation wise is it bolt on, drill screws...???

heres is the link to the one i believe you suggested:

https://www.boatersworld.com/product/MP80825803.htm


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## tccanoe (Oct 27, 2010)

You got it Hink, Now as far as painting. I've seen guys that know what the're doing take raddle cans and do a pro job. Get those add-on triggers that snap in place on top of the spray can. Get the self etching primer at Wal-Mart in the Auto Section or order on line. Short even bursts etc. Wipe down your boat with acidtone just prior to priming. I'm no expert. Snoop around the site and use the search function on painting. Lots of guys paint and do a pro job. As with all types of painting, prep work is the key. Shoot us some pics of your boat now and as it progresses. It's also a good way to get a date. "Hay, would you like to go for a pick-nick in my boat?" You can't miss. Better than a Corvette.


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## mhinkle1990 (Oct 28, 2010)

tccanoe said:


> You got it Hink, Now as far as painting. I've seen guys that know what the're doing take raddle cans and do a pro job. Get those add-on triggers that snap in place on top of the spray can. Get the self etching primer at Wal-Mart in the Auto Section or order on line. Short even bursts etc. Wipe down your boat with acidtone just prior to priming. I'm no expert. Snoop around the site and use the search function on painting. Lots of guys paint and do a pro job. As with all types of painting, prep work is the key. Shoot us some pics of your boat now and as it progresses. It's also a good way to get a date. "Hay, would you like to go for a pick-nick in my boat?" You can't miss. Better than a Corvette.



haha will do. I'm heading to orlando this weekend for halloween horror nights at universal then when i get back i will definitely take some pics. and for the pick-nick idea.....my gf hates my boat because it supposedly goes too fast lol....its a jonny not a speed boat hahaha


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## tccanoe (Oct 28, 2010)

Guess I'll have to swallow harder to get the shoe strings to go down. Didn't know you could have school, job, tin boat and a girlfriend. My hero.


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## mhinkle1990 (Oct 28, 2010)

hahaha i appreciate it tc. it gets hectic sometimes but its worth it in the end!


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