jack plates/what is their purpose/

[Newyota]

Just got my first boat last summer.A 14' lowe jon.I mainly will be fishing a river that is very rocky and running at low speed mostly.I recently had a rock /prop gaurd made, but was wondering if buying one of the mini jack plates would be even more help?They lift the motor 3" up and back about 3".This would also give me more clearnace for the control so it does not hit the back of my seat.Also, what is the main purpose of a jack plate?Do they help get you on plain better?thanks

 

[JB]

Re: jack plates/what is their purpose/

Jack plates are for fine tuning the height of the outboard for peak performance without porpoising or ventilation. They generally don't have much effect on initial acceleration or minimum planing speed, that is something that hydrofoils are for if correctly rigged.

Jack plates do usually allow the anti-ventilation plate to be rigged higher, which would allow shallower navigation.
I used both on Sunshine III, along with a SkegGard, with good results.

 

[Bamaman1]

Re: jack plates/what is their purpose/

A jack plate lets you tailor the engine height for best speed. Some will also use them on a hull/engine combination that just doesn't perform right.

I've never seen a jack plate on an aluminum fishing boat.

You'll mainly see them on high performance boats and bass boats. Some use the $1K hydraulic jack plates of they often fish in shallow waters. I have seen them on some center console boats left in salt water to get the engine/lower unit completely out of the water.

 

[kfa4303]

Re: jack plates/what is their purpose/

Well now you have....



I have a jackplate/transom riser on my 14' semi-V hull tinny. Not only does it help get the anti-vent plate to the optimum height in relation to the keel, which can be a bit of a problem with vintage OMC motors, but it also lets me run in skinnier water, which is the name of the game down here in FL. You'll see all kinds of jackplates and transom risers on everything from Gheenoes (essentially unsinkable, hot rod canoes made here in FL) with nothing more than a 3 hp - 10 hp motors to super duper Bass boats and offshore fishing machines with +200 hp motors. Check out bobsmachineshop.com and/or atlas jack plates if you're interested in buying one. You can also make one yourself out of a few pieces of thick aluminum angle. Do a search here in the forums for lots of versions and variations. Here are some pics of various plates and configurations:

 

[BassCanada]

Re: jack plates/what is their purpose/

Iam confused.. I have read posts on here where guys say no jackplate for anything under 150hp.. And then guys that say no jack plate for anything but V6 engines.. or is it V4.. So whats up??

I have a 1887 Procraft with a 135hp mariner on it.. Should I put a jackplate on it??? Or am I wasting my money..
Or should I maybe just put on transom setback spacers??

 

[IamCanadian]

Re: jack plates/what is their purpose/

Is your anti anti-ventilation plate close to the same level as the keel of your boat? If so, I wouldn't bother with a jack plate.
Only time I have ever had to use one was to put a 225hp Yamaha LS onto a 16ft FG boat with a 15" transom. Just to raise the motor up the 5 inches it needed.

 

[glenn property of pam]

Re: jack plates/what is their purpose/

if you lift a engine behind the boat then the prop is in a blocked water flow behind the transom so you need to move the prop backwards to get in unblocked water. i run a 4" jack plate that im running about 3" higher than normal. if i wanted to go real high then a 6" might have been a better idea. on the down side the jackplate does move the center of gravity of the boat especially when you are not moving, can cause a more slipage on the prop and it adds additional stress to the transom. if you fish in shallow water then the good things out weight the bad things.
big engines also help in shallow water as they can kick you up on plane quickly but ive never seen anything that says not to be used on lower hp

 

[kfa4303]

Re: jack plates/what is their purpose/

Iam confused.. I have read posts on here where guys say no jackplate for anything under 150hp.. And then guys that say no jack plate for anything but V6 engines.. or is it V4.. So whats up??

I have a 1887 Procraft with a 135hp mariner on it.. Should I put a jackplate on it??? Or am I wasting my money..
Or should I maybe just put on transom setback spacers??

Well like I said, lots (almost everyone) runs a jackplate/riser of some sort in my neck of the woods (FL) where you want to get as shallow as possible. You'll see 3-5 hp outboards on jackplates where guys are trying to squeeze every bit of power and every inch of draft out of their motors. Checkout cutomgheenoe.com or microskiff.com for some fun examples of small hp motors on jackplates running in skinny water. Of course, ultimately you just want the anti-vent plate to be level, or slightly higher than the keel of your boat. Assuming that it is, you're probably ok.

 

[Newyota]

Re: jack plates/what is their purpose/

So, would it benefit me?Would it hurt anything to get one if I do run inlakes and deeper water?

 

[Bob_VT]

Re: jack plates/what is their purpose/

Save your money. You will not see much of a benefit from a jack plate. They are NOT designed for small outboards.

You are running a 9.9 right? Just keep your rock guard.

 

[kfa4303]

Re: jack plates/what is their purpose/

Save your money. You will not see much of a benefit from a jack plate. They are NOT designed for small outboards.

You are running a 9.9 right? Just keep your rock guard.

So, would it benefit me?Would it hurt anything to get one if I do run inlakes and deeper water?

Sorry Bob, but you're wrong. They're absolutely designed for small outboards (see previous posts). In fact, it's quite the little cottage industry down here on the Gulf Coast. Maybe they just aren't very popular in Vermont. Check out Microskiff.com, bobsmachineshop, atlasjackplates, etc..... (see link below)

Image Search Results for small outboard jackplates

While the jackplate won't effect your open water performance much, it should reduce your draft a few inches which may be handy in shallow, rocky water where every inch counts. I've also found that the boat steers a bit more easily due to reduced drag of the motor. Just be sure its lower unit is submerged enough to pump plenty of water at all times. It takes a bit of trial and error to get just the right height on the motor, so be patient and methodical. Also, be sure that you can corner at speed without having a blowout. There are all sorts of designs out there (electric, hydraulic, manual), but i would stick with something simple like one of the solid, fixed units and/or a DIY version made from aluminum angle.

 

[Bob_VT]

Re: jack plates/what is their purpose/

Considering the skill level and newness to boating of the Original Poster ...... I am correct. I would rather see more experience and the ability to use the shallow drive on the 9.9 before any monies are spent.

The last question was about deeper water which also not necessary.

We are talking about a heavy (maybe heavier then normal jon boat if they have glued in all that carpet) small boat. I am looking out for the benefit of the iboat member (their wallet) and not the cottage industry people.

I am surprised people have not asked about his present set up.

To the Original Poster Newyota...... at the early stage of your boating experience I would save the money and concentrate on the overall set up and balance of the boat.

 

[Newyota]

Re: jack plates/what is their purpose/

ok thanks

 

[NSBCraig]

Re: jack plates/what is their purpose/

It's like anything, sure it would help in certain situations (shallow water) but does that mean you should spend money on it you could use for other things that would benefit you more?

Only you can make such decisions.

If you can locate an inexpensive manual plate or materials to make one, when the opportunity arises, I'd do it in a second. But there are probably a couple other things you could spend that coin on too.