Motor Height

[John Foster]

I put a 5" manual jack plate on my 170 last year and am finally getting to mess with it's set up.



I have heard to set it as low as it will go an lift it 1/2" at a time till you start to loose speed or waterpressure then back it down till you get the best hole shot and top end without loosing water pressure.



I have also heard that a good starting point is 3" below the pad. Ok, now I am a bit dense at times:blink:, So what is 3" below the pad. The top of the prop? or the prop shaft??



Wouldn't the top of the prop be out of the water if I set the shaft only 3" down. 13 1/2" dia pro divided by 2 equals 6 1/4". Wouldn't the prop be 3" out of the water?? I know I missing something hear:unsure:



John

 

[mike mcmenamin]

john:



prop shaft, and not to be wise but 13 1/2 divided by two is 6 3/4.





mike

 

[TrepMan]

john - I have a 4.5 manual plate on my nitro (Rich installed it) don't know if hte 170 is similar in hull but depending on the prop I use, I may have mine as low as 5.5 inches below the pad with my 25p 13.25 diameter Turbo, but it wants to run around 4 inches below pad for my 24p 13.75 diameter Bandit prop. The 3.5 inches seems to be a good starting point for the 150+hp boats.



For measurements, this was a great help to me




http://www.bassboatcentral.com/measuring.htm

 

[John Foster]

Thanks Trep. I forgot you have the 700 Rich used to have.



See Mike, I told you I was a bit dence:blink::blink:

not to be wise but 13 1/2 divided by two is 6 3/4.

 

[Mini]

1/2" is a mile when dealing with a jackplate. move it maximum 1/4" at a time. 1/8" is preferred.

 

[Mike Zechman]

propshaft centerline, and when I did my 6"manual plate I started at 3.5 and went in 1/4" increments like Mini said. I also played with different props as well, that my dealer let me borrow for free to get my prime set-up, it took a few hours, but she runs with the boys now

 

[TrepMan]

John - If you don't make sure you ALSO ADD A WATER PRESSURE GAUGE, that is Key as you raise the motor to ensure you have enough cooling water to not blow the motor!

 

[John Foster]

Thank everybody.