Jack plate? - 15 hp on 12' Deep V. Is it worth it?

[aeviaanah]

I was thinking of building a jack plate for my 12' Deep V. I just purchased a Mercury 15 HP 4 stroke, its a few weeks out. You think a jack plate is worth it in this situation? The guys at bass pro shop didnt think so.

 

[FuzzyGrub]

I was thinking of building a jack plate for my 12' Deep V. I just purchased a Mercury 15 HP 4 stroke, its a few weeks out. You think a jack plate is worth it in this situation? The guys at bass pro shop didnt think so.

You have to mount your engine to see where the anti-cav plate is in relation to the bottom of the boat.

 

[Ictalurus]

I'd be a little hesitant about putting a 15 on a 12', what is the max HP rating on your boat?

 

[wihil]

My 12' can take up to an 17.5hp, but I'd be more worried about the weight on the transom. A 4 stroke 15hp motor weighs a whole lot more than a 2 stroke for the same displacement.

It's gonna be fun when it's on, that's for sure.

C

 

[BaitCaster]

depends on where your cav plate sits in relation to the bottom of your transom. I have a mini-jacker for my 18hp and it lifted the cav plate about an inch above the bottom of the boat. I got a couple more mph with the jack plate, but I didn't do it for speed. I did it to create clearance for my side scan transducer. I wouldn't have done it otherwise.

 

[V8_TITAN]

ill trade you my mercury 9.9 2 stroke for your 15 it weighs about half as much and will push you almost as fast ! lol.. as far as the jack plate, Im not sure, but you may be in the market for a lighter motor. did you order it brand new ?

 

[PATRIOT2]

Option 1:
Forget the jack plate and invest in pods if you have to put the new motor on this small hull.
Option 2:
Forget the jack plate, the pods, and the 12' hull, and invest in a 15-16' hull for your brand new motor.

Good luck.

 

[aeviaanah]

I was thinking of building a jack plate for my 12' Deep V. I just purchased a Mercury 15 HP 4 stroke, its a few weeks out. You think a jack plate is worth it in this situation? The guys at bass pro shop didnt think so.

You have to mount your engine to see where the anti-cav plate is in relation to the bottom of the boat.

Ok, what is the anti-cav plate?

I'd be a little hesitant about putting a 15 on a 12', what is the max HP rating on your boat?

The boat was made in 71' Similar models are rated at 15 hp...i have beefed up the transom a bit from what factory did as well. You dont think its a good idea? I havent paid for the motor yet, just a down payment. They should be able to refund it.

My 12' can take up to an 17.5hp, but I'd be more worried about the weight on the transom. A 4 stroke 15hp motor weighs a whole lot more than a 2 stroke for the same displacement.

It's gonna be fun when it's on, that's for sure.

C

What kind of 12' boat you got?

depends on where your cav plate sits in relation to the bottom of your transom. I have a mini-jacker for my 18hp and it lifted the cav plate about an inch above the bottom of the boat. I got a couple more mph with the jack plate, but I didn't do it for speed. I did it to create clearance for my side scan transducer. I wouldn't have done it otherwise.

What length is your boat? What exactly is a cav plate?

ill trade you my mercury 9.9 2 stroke for your 15 it weighs about half as much and will push you almost as fast ! lol.. as far as the jack plate, Im not sure, but you may be in the market for a lighter motor. did you order it brand new ?

Yes I ordered it brand new. Man, all the sudden everyone tells me to watch out with the 15 on the 12' boat. Lots of people, including bass bro shop told me it would be ok. I up to hear both sides tho.

Option 1:
Forget the jack plate and invest in pods if you have to put the new motor on this small hull.
Option 2:
Forget the jack plate, the pods, and the 12' hull, and invest in a 15-16' hull for your brand new motor.

Good luck.

Well i can always ditch the 15 hp...you think its a bad idea? Pods?? Do they add buoyancy to the hull? I just bought the 12' boat and am doing lots of work on it.

 

[FuzzyGrub]

Ok, what is the anti-cav plate?

It is the first flat plate above the prop. While it is called an anti-cav(itation) plate, it really is an anti-ventilation plate. Helps prevent air from sucking into prop. You get lots of rpms with little forward motion.

 

[aeviaanah]

Ok, what is the anti-cav plate?

It is the first flat plate above the prop. While it is called an anti-cav(itation) plate, it really is an anti-ventilation plate. Helps prevent air from sucking into prop. You get lots of rpms with little forward motion.

Thanks!
What you think about this motor on my 12' deep v?

I need to figure this out so I can cancel the order If needed.

 

[FuzzyGrub]

What you think about this motor on my 12' deep v?

I need to figure this out so I can cancel the order If needed.

I assume the CG plate is missing. From the one picture that I saw in the other thread, the 12'er looks to be of the typical style where the cg plate has a max HP of 10HP. A picture doesn't provide any dimentions. If you did the math, and got 20HP, you should be good. If you want to check your work find a new boat spec that matches your boat. The CG/liability issue can be read in many a thread. You have to make your own call there.

Now, will your boat be reasonably safe, from a power/handling perspective? Going with a 12'er with a 10hp max rating, and putting on a 15hp, would be a "fast" and "fun" boat. Probably would not have any high speed handling issues. Now, you have added additional weight, so you are basicly taming that extra hp. As far as transom goes, most mfger of 12'ers also make a 14'er of same style/construction that typically have a 15HP rating. The transoms are usually identicle.

A 15HP 4 stroke is heavier than a 2 stroke. That amount of weight would go against your boats overall capacity, (which we don't know either). It is easy to get too much weight in the boat with these kind of mods. Will those 30 or so lbs break the camels back? I wouldn't think so, but you can adjust elsewhere. The extra weight on the transom will flex it a little more. You could add some additional transom support for piece of mind.

 

[aeviaanah]

What you think about this motor on my 12' deep v?

I need to figure this out so I can cancel the order If needed.

I assume the CG plate is missing. From the one picture that I saw in the other thread, the 12'er looks to be of the typical style where the cg plate has a max HP of 10HP. A picture doesn't provide any dimentions. If you did the math, and got 20HP, you should be good. If you want to check your work find a new boat spec that matches your boat. The CG/liability issue can be read in many a thread. You have to make your own call there.

Now, will your boat be reasonably safe, from a power/handling perspective? Going with a 12'er with a 10hp max rating, and putting on a 15hp, would be a "fast" and "fun" boat. Probably would not have any high speed handling issues. Now, you have added additional weight, so you are basicly taming that extra hp. As far as transom goes, most mfger of 12'ers also make a 14'er of same style/construction that typically have a 15HP rating. The transoms are usually identicle.

A 15HP 4 stroke is heavier than a 2 stroke. That amount of weight would go against your boats overall capacity, (which we don't know either). It is easy to get too much weight in the boat with these kind of mods. Will those 30 or so lbs break the camels back? I wouldn't think so, but you can adjust elsewhere. The extra weight on the transom will flex it a little more. You could add some additional transom support for piece of mind.

Fuzzygrub, thanks for the post...this is the kind of detailed post I needed to read. I have beefed up the transom quiet a bit. I'm more worried about weight and handling in the tail end as opposed to power.

58" Transom width (at top)
145" Total length
15" Transom Height

 

[PATRIOT2]

Something else to consider is how you are going to steer it. The same hull can be rated for 15HP if it is tiller steer and 25HP if it is remote.
Since you asked about pods, here are pics of pods I plan on fabricating if I keep this 14' hull (remote steer) and mount a new 40HP, even though I'm looking for a wide bodied 16'
You can go on the "Beavertail" website for info on pods. I'd go with bolt-on versus weld-on pods though.
Also, a pic that shows the cav plate angle I have to run to keep the bow down while on plane. Lowe's spec for the distance between the bottom of the boat and the cav plate is about 1.5"

 

[aeviaanah]

Something else to consider is how you are going to steer it. The same hull can be rated for 15HP if it is tiller steer and 25HP if it is remote.
Since you asked about pods, here are pics of pods I plan on fabricating if I keep this 14' hull (remote steer) and mount a new 40HP, even though I'm looking for a wide bodied 16'
You can go on the "Beavertail" website for info on pods. I'd go with bolt-on versus weld-on pods though.
Also, a pic that shows the cav plate angle I have to run to keep the bow down while on plane. Lowe's spec for the distance between the bottom of the boat and the cav plate is about 1.5"

I see what you are talkin about now. Thanks for the post. I can make a set of pods rather easily at my metal shop. What thickness and material you going with for yours? These basically just add buoyancy to the back end right? Lookin good man.

 

[lovedr79]

Nice! I need a set of pods on my boat........

 

[FuzzyGrub]

I'm more worried about weight and handling in the tail end as opposed to power.

If you downsize your plans to just one battery and that is forward, that will more than make up for the weight difference. Moving the six gallons fuel tank forward is another option if you actually have issues. That is about 36lb when full.

 

[aeviaanah]

I'm more worried about weight and handling in the tail end as opposed to power.

If you downsize your plans to just one battery and that is forward, that will more than make up for the weight difference. Moving the six gallons fuel tank forward is another option if you actually have issues. That is about 36lb when full.

Good to hear, I need to get the motor and test the waters and weight issue. A trolling motor up front should help a bit too. What do they weight about 30 lbs?

 

[aeviaanah]

I want to get a few more opinions on the subject before I choose to or not to build this jack plate. My boat is actually a mod-v.

Do you think a jack plate will help a 12' mod v with a 15 hp 4 stroke?

Please don't consider cost or time.

 

[FuzzyGrub]

I want to get a few more opinions on the subject before I choose to or not to build this jack plate. My boat is actually a mod-v.

Do you think a jack plate will help a 12' mod v with a 15 hp 4 stroke?

Please don't consider cost or time.

Maybe I missed it and/or its in another thread. Did your motor arrive, mount it, measure where cav plate is, and have any performance numbers?

Cav plate way lower than bottom: worth doing, noticable improvement.

Cav plate near level with bottom: slight improvement.

Cav plate 1-2" above bottom: probably not worth building.

PS: Also better to check visually while on plane, vs measurement.

 

[hotshotinn]

To answer your question the answer is

NO​