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Discussion Starter · #1 ·
Hey guys i have a 05 classic with TSG electric Jackplate, I have recently went from a Merc 25 hp 2strk to a Hatsu 20 Hp 4 stroke, I finally installed my tiny tach and bobs cavitation plate. Here is my dilemma. The stock prop on the motor is like 9.8 pitch, With the jackplate all the way down i am hitting 6100 rpms, but when i raise jackplate i have reduce throttle to keep from going over the 6100 due to the rpms going up when i raise jackplate. Also with the merc i could lift jackplate all the way up with no ventilation at all i could even take full turns with it all the way up, with the new motor i cant even get it half way without major ventilation, What i am trying to do is be able to run jackplate all the way without ventilation and under 6100 rpms, which prop should i go to?


Alex
 

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8 pitch on a 20hp /noe ;D
Y'er already tapping the rev limiter.
Time to increase pitch and cup to get you back down to 5500 to 5900 rpm.
An 11 or 12 pitch with cupped blades will do you better.
 

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Talk to Marc at Powertech.....get a 3 blade s.s SRA 11” pitch with standard cup.
 

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Discussion Starter · #8 ·
10-4, i mainly would like to just be able to lift my jackplate again, but this ventilation is killing me,

i tried a 4 blade 11 pitch and and lost all ym top end and still had ventilation problems.


Alex
 

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Discussion Starter · #9 ·
Also i forgot to mention that i did try out the 9.25 dia x 11 pitch 3 blade, I was able to lift the jackplate some while staying inside my rpm. So would i need to go with a 12in pitch 3 blade powertech? or higher? With my jackplte i have about 4 in of lift, it goes high lol.



Alex
 

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Discussion Starter · #11 ·
I can bring the boat and all the props i have down to palm coast if need be, i really need to get this figured out, i fish a alot of shallow water and not being able to lift the jack plate is killing me lol.


Alex
 

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Quiet ramp, rarely busy, great for testing and adjusting

http://www.flaglercounty.org/facilities.aspx?page=detail&RID=10
 

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Pick your time, I live 10-15 minutes away, depending on the line at my coffee stop.

This time of year I'm done fishn' by 8:30 am.  ;)
 

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Alex
A few years ago I had a Classic (with a manual jack plate) that I put a new 20HP Hatsu motor on (great little motor).
After break-in, I started fooling around trying to find the correct prop. Below are some excerpts from my test log:
05/07/10 – Ran boat to test the stock Prop (9.25X10) that Soles Marine put a heavy cup in. Ran in a light chop (2”-3”) with a light load.
Jacked up 2”, I saw 27.1 MPH at 6050 RPM (Good hole shot and turns)
Jacked up +1/4” (21/4” high), I saw 28.1 MPH at 6090 RPM (Good hole shot and turns)
Net increase in speed, 1.6 MPH/Net decrease in RPM -192.

06-10-10 - Wind 10-15 with a 1’ chop
Jacked up 1” w/ Aluminum prop saw 28.2 MPH @ 6150 RPM
Jacked up 1” w/SS prop w/cup, saw 26.2 @ 5700 RPM tries to blow-out coming out of the hole. Good on turns.
Jacked up 3/4” w/SS prop, saw 26.7 MPH @ 5690 RPM no blow-out on hole shot or turns.
The SS wheel I went with was a Power Tech SRT 9-1/2”X10 SS wheel with extra cup.
Hope this helps you find your prop.
 

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Discussion Starter · #20 ·
Thanks for the info Barry, My prob is i am running an elctric jackplate that has 4 1/4 in of travel, with an 9.25 x 11 pitch i can raise jp up almost half way with no issues and still performs well, I am looking to go higher, when i go high my rpms shoot through roof and and I have ventilation. I am gonna get with brett here soon so he can see what it is doing so he can make some suggestions on what i need.

Alex
 
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