Jackplate on a sneakboat?

Matt Masters

Active member
Has anyone ever run a jackplate on a sneakboat? The reason I am asking is because I'm not a little guy by no means and trying to get a little more performance while I am in the boat because of the weight bringing the boat down in the water more. I have a A.A. Blacjack w/an 04 15hp Mercury 2-stroke. It runs great planes out great and runs in mid to upper 20s. Any suggestions? I will probably but a different pitch 4 blade prop on it to help some.
 
That is with just me in an empty boat. I had a buddy of mine get in the boat with me to kind of give me an idea of how the boat would perform loaded down and it wasn't where I wanted it to be.
 
I would think that changing the prop would be better than a jack plate.

That boat rated for 25HP. Maybe thats your problem?
 
I had a 20hp Mercury on it and it was scary. I'm gonna start with a prop and go from there.


Scary maybe if you are going through flooded timber. A buddy of mine has the broadbill with a 25 yammy. Sucker can move with both of us and gear but I've never felt like I was going to "die". Not sure how a 15 wasn't enought and then a 20 was scary.
 
My gut says a jack plate might get you another 1-2 MPH, no more. You go a touch faster because the motor can run a bit higher and there is less drag from the lower unit. I'd recommend a small manual jack because they are much lighter. TSG Customs makes a nice one that you can adjust on the water. Bob's Machine makes another popular one.

http://tsgcustom.com/default.aspx
http://www.bobsmachine.com/Products/jackplate_mini-MMJ.cfm

You will definitely see the biggest difference with the right prop IF your current prop isn't already where you need to be, but you really need a tach to figure that out. Tiny Tachs are cheap if you don't have one hardwired in from the factory. Props are too expensive to just start guessing and buying. Once you have the data from you current prop and your RPMs at WOT, Mercury Marine has a prop calculator that you can plug the data into in order to get an idea of what to buy for your needs.

http://www.mercurymarine.com/propellers/prop-selector/#

If you really want to get crazy, you'll need tabs. Manual tabs are very light and very simple and they will let you trim the motor separate from the boat. TSG Customs makes them also.

To see the most benefit, you would need to do all three things. Adding them over time is reasonable. I'd start with the jackplate because that might affect the prop pitch some. You're not going to get a race boat out of it, but you might gain another 5-6 MPH total, gain a bit more MPGs and lose 1-3 inches of running draft. It would be worth the investment to me, but it would end up being a bit under $1K by my estimates, so it might be silly to you.

Nate
 
Matt

If you decide you want to try a jack plate I have one of the Bob's Machine Shop mini Jack Plates that I'd sell you for $50 & shipping.
 
Nate-thanks for all the tips and advice.

Tim-shoot me a PM and I'll probably take it off your hands.

The 20 I had on it was a hot rod in its own for some reason. It pushed a 16x44 Go Devil with a .125 hull 32mph empty. When I was looking for another motor as many of you guys know it is hard to find 15hp-25hp that is a two stroke in good condition. I came very close to buying and 07 25 Yamaha but I know that would have pushed the boat to the scary level again. With the 20 I had it was pushing 40mph.
 
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