Installing a simple small jack plate?

[wmbreck]

I have a 15' fiberglass boat that is underpowered with only a 28 hp Johnson outboard.
Top speed with a gps and one driver was 23 mph. But it would be nice to do that with 2-3 people if possible - or even 18-20 mph with 3 aboard.

After researching here, I've discovered that 'part' of our problem is that the motor is a long shaft meaning everything is about 4" under the surface and creating extra drag -especially the hydro-foil that is what allows me to plane eventually after about 2-3 minutes at full throttle.

It appears, from what I see here also, that a manual jack plate is my best bet and I can get one for $100-150 for a motor that small. My question is this. Exactly how hard is this simple smallish jack plate to put in? Is it pretty much a matter of drilling the holes in the transom 'properly' and then connecting the metal plates with the provided bolts and sitting the motor back on top at the proper depth?

Thanks for any help or advice on this.
Bill

 

[smallboatlover]

Re: Installing a simple small jack plate?

how about to try to look for a repower. and sell the current motor. you can look for a 50 hp motor and that will get it going nicely i got a 50 hp on my 14' and it gets on a plane in seconds i also have the hydrofoil. After you get another motor you can sell the other one and recoup some of your money. A jack plate is just covering up you real problem a under powerd boat

 

[wmbreck]

Re: Installing a simple small jack plate?

You are exactly right about the HP. Someday I will get a 40 or 50. But for now it is simply economics. I'm even splitting the price of the jack plate : So even 2-4 more mph would satisfy temporarily and take even a little of the pressure off the current motor and hopefully get a little better fuel economy. Thanks.

 

[lncoop]

Re: Installing a simple small jack plate?

On that little rig you don't even need the jack plate. You can simply interpose a small piece (or pieces) of square tubing between the motor bracket and top of the transom. Voila! Hillbilly jack plate!

 

[wmbreck]

Re: Installing a simple small jack plate?

Hi.
I already did something like that with a board (screwed down of course from the top) "BUT" it brought the 2 screw claps that fasten the motor to the transom right to the very edge and I only gained about an inch. Made me nervous to see the motor that close to coming off and again did not give me the 3-4" I probably need to eliminate the drag and get the foil up and the prop near the surface. What I did do was put a one inch board under the motor on the outside horizontally which trimmed it out another inch. I picked up 2 mph but can't go any more because the prop is almost starting to face downward.
Thanks.

 

[wmbreck]

Re: Installing a simple small jack plate?

Here is a youtube (hope it works) from 2 weeks ago on Lake Ontario with my son (180 lbs) alone driving and probably at about 21-22 mph. Trim tilt is all the way out which gives us the top speed we can get and the most rpms. He hit 23 mph driving alone once on the gps going with the waves. My goal is to milk 25 mph of of this if I can get the long shaft prop and foil raised up to where they should be in relation to the surface. Again everything now runs 4-5" under the water at full speed causing who knows how much drag? A bigger motor may not be affected by this as much. But with only 28 horses, I am thinking a jack plate would really help reach the max rpms and top.

http://www.youtube.com/watch?v=1i70nyuPy0g

Stiil looking for an idea of how hard or easy a small manual jack plate for a 28 hp long shaft will be to install on this thing.

Thanks.

 

[FAC]

Re: Installing a simple small jack plate?

I too had an underpowered 15' boat with only 25hp mine was also a longshaft motor I made a jack plate out of 3/4" ply two layers thick, it worked great for me. It could plane with three smaller adults or two 180lb people, I was completely satisfied with my setup. my boat was a little different though it was a trihull with very little deadrise.

 

[wmbreck]

Re: Installing a simple small jack plate?

I thought of that. Did you put one piece on the inside and one on the outside and drill throgh the transon to connect them? or put both together, and where, if you don't mind me asking how you devised it? Thanks

 

[FAC]

Re: Installing a simple small jack plate?

I laminated them together and bolted them as one piece to the outside of the transom. It was essentially mounted like a conventional jack plate.

 

[wmbreck]

Re: Installing a simple small jack plate?

Sounds 'doable'. So your drilled through the transom and set the wood to the height your desired and bolted them in place?
You don't happen to have any photos of what you did do you?

 

[FAC]

Re: Installing a simple small jack plate?

pretty much, I used the holes that the previous motor was mounted with. I dont have any pictures and I dont have the boat anymore sorry

 

[wmbreck]

Re: Installing a simple small jack plate?

Just one last question. Did you have a piece of plywood inside and one on the outside and bolted through them together to the transom ? Would seem like too much pressure to have them together on either side.
Thanks again

 

[hidef]

Re: Installing a simple small jack plate?

You want to laminate the two pieces of 3/4 inch plywood together and bolt that to the back of the transom using 4 half inch bolts with large flat washers. If you get a bolt template for a 40 horse or larger outboard you could drill the holes so that they could be used for a larger outboard later on. If you are concerned about strength you could put 1 1/2 aluminum angle around the outside edges to give it extra strength although that would be overkill. You will want to use a good adhesive however when you laminate the pieces together to make it solid.

 

[zopperman]

Re: Installing a simple small jack plate?

This might help:

http://forums.iboats.com/showthread.php?t=321432

If you use wood I'd recommend glassing it with 1708

 

[wmbreck]

Re: Installing a simple small jack plate?

I'm 'Considering' building a wooden plate for the above long shaft issue.

But I still have not heard back from someone who knows if installing a small store bought manual jack plate ($100-150) is easy and pretty straight forward. Is it just a matter of drilling the transom and bolting it on pretty much?

Anyone know?
Thanks!

 

[Whoopbass]

Re: Installing a simple small jack plate?

It should be straight forward as long as your bolting it all the way through the transom.

 

[wmbreck]

Re: Installing a simple small jack plate?

Thanks much. I'll consider both of my options!

 

[wmbreck]

Re: Installing a simple small jack plate?

May have found my best and cheapest option for the long shaft issue and jack plate deal
Pro Bass Shops $76 - takes up to 35hp. MIne is 28.

Product link on their site = http://tinyurl.com/3cx2k8o
---------------------------------------------------
Overall Rating: 5 out of 5 Great Product,March 10, 2011 .
Advantages: Value for money. This product is awesome it was just the solution I
needed for my 16' aluminum boat. I have a short recessed transom and a long shaft tiller
motor. My boat would take a bit to plane and I was loosing top end speed. I installed the
mini jacker and BAM problem solved! planes super quick and gained my top end speed and
then some. I was very impressed with the performance advantaged of the mini jacker and
also the fit & finish and easy install. The value for the $$$ is right on don't think
twice get it I should have got this thing sooner."

 

[Willyclay]

Re: Installing a simple small jack plate?

Here's another DIY option if you have not already purchased one. Please post a follow-up report on what you did and how well it works. Good luck!

http://www.dillon-racing.com/jackplate/index.htm

 

[wmbreck]

Re: Installing a simple small jack plate?

View attachment 107341View attachment 107342

Lookie what I bought. Amazing piece of hardware. can;t wait to see how it works this week if I can get it on!