Jack PLate???

[lwr1967]

At the risk of sounding like an idiot (I do it all the time) what is the purpose of a 'jack plate'???

 

[merc245]

First theres two 2 types, adjustable & static (non-moveable) and of the adjustable type, there is a sub group of hydraulic (electriic) or manual.
Both types are after the same effect of lifting the out board motor up and out away from the the transom.In doing so there is several performance gains to be had.First and for most, there is less parasitic loss by lifting more of out drive out off the water.Second with the propshaft closer to the surface it allows the prop to rotate easier thus allowing for large pitch prop to be turn thus the ablity to generate more speed under the same rpm & hp range.Thats where the extra setback factors in also. You want the prop shaft to be as close to parallel with the surface of the water for the most efficent forward thrust.Having any setback will create more leverage in help lifting the hull in that operation.

Hope that clears up a thing or two!!!!


Anytime, merc245

 

[lwr1967]

I appreciate that. It was about what I figured, but wanted to make sure. I've got a Johnson 120 or 125 to put on my Trimate, but the guy who has it says he thinks the lower unit may be too long (I haven't seen it yet) and I guess a jack plate woyuld help correct that?

 

[Boston Predictor]

Also, From what I understand the Jackplate (setback) allows the prop to run further back in "cleaner" water to get a better bite

 

[83PREDICTOR]

You are going to want to run a 20 inch saft on that boat.