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Motor height

Bought a 24' bay stealth recently. Ran it for first time a few months ago. Topped out at 53mph.
Then I put on an 8' manual jack plate. Installed it all the way lowered. Lost some mph. Went down to about 47mph
So I jacked it all the way up. Ran it and lost more! Tops out at about 43mph now.
Is it too high? Feels like when turning it doesn't catch the water. I attached a pic to show the water line while running about 75% throttle.
The prop shaft seems to be even with the bottom of the hull.

Any help or opinions is appreciated.
Not always plug and play
' Every action has an opposite reaction' , I think it was Enstein said that , I do know from when I put a manual jack plate on my old refurbbed 1978 Mako 20 w/140 , it wasn't no where near 'Plug and Play ' , it took a lot of tweeking , at times I was thinking I made a mistake , I must have move it up and down 40 times , put wedge shims in and out , I ran at least 10 different props and found the one with the best bite and least cavatation in turns was a 4 blade which was reworked with extra cup and the hub was drilled for extra exhaust to help get on plane from what I was told , also ran an Edge anti-cavatation plate over the top the prop which was a must running tight winding bayous as it would cav out ----- I should have never sold that boat , it was a fine running , dry boat in rough water , it would only run right at 45 mph and running down Terra Beouf to Black Bay in the morning all the bigger Well Crafts , Aqua Sports , Grady Whites would pass me by running 50-55 mph , when we hit Stone Island on the way to Battledore I was passing them ----- that boat rode well with out a jack plate , once it was tweeked out it rode great
So you did find the sweat spot? We\'re you able to have the motor higher and also gain mph?
sweet spot
To answer your question : Did I find the sweet spot ? .... yes , but not without doing other modifications , I would say the jack plate alone, over all , hurt more than helped , I was very disappointed with it right off the bat , and it cost a lot of test runs and money to get it right, I borrowed so many props and never did really find the right one , got one close and then bought one and had it custom tuned ------ I would go one way and improved some things and hurt others and going the other way and caused other problems ..... I remember going down with it and having more control in turns but lost speed and threw rooster tails off both side the cav plate straight up behind the transom , went up too high and had no control in turns and it would cavatate bad and I could lose it in a tight bayou and spin out .... after finding the right prop , hydraulic trim tabs and a cav plate it ran like another boat ------ I don't remember the exact numbers on speed but it wasn't a lot ,around 5 mph max , the boat was heavy fiberglass vee , what I really liked about it after it was all set up with the jack plate , trim tabs , prop and cav plate wasn't speed , but a much better ride in rough water , the ability to run at a much slower RPM and stay on plane , the ability to jump up on plane without going thru the extreme bow rise thing , which helped getting up in swallow water ------- I think the design of the hull has a lot to do with the results you would get , some boats might be plug and play , others ain't so easy I know cause I went thru it
all I know is I was told cav plate even with bottom of boat?
'Spirals of Upgrading'
Geronimo sez... 'Should Have Left Good Enough Alone'...cheers
like they say if it aint broke don't fix it!!! I agree!!! 53mph I would have been happy as heck?
Reason installed
Oh boy. I hope I don't have to go through the same issues.
The bay stealth has a recessed motor. In order for me to put the power pole on without drilling into boat I had to get a couple motor plates. One was almost as expensive as the jack plate. So I just got the jack plate and mount that hooks power pole to it. As you can see from pics.
I assumed the jack plate would only help. :/
picture not to good u got it running back at 53mph????
can of worms
...the cavatation plate is at the bottom of a boat without a jack plate ...... but.....when you use a jack plate or a Gill bracket , Armstrong bracket (transom extension) it isn't the same , you go so much up for so much back , all types of hulls have different reactions , and the prop makes a difference ..... I have seen boats 5 inches up on a 6 inch plate , and others 2 inches up on a 12' , so there is really no rhyme for reason , on boats with transom extensions a boat that is a long shaft 25 inch will run a short shaft 20' --------- can anyone say ' opened up a can of worms '
I am optimistic. I'm hoping that a few more inches lower and I can have her running in the 50's again.
I will for sure repost back next test run.
Hopefully accompanied with a good fishing report!
I would think you would be burning more fuel also? not sure? good luck hope you get it right!!!
I think once he gets it all tuned in , the mpg and mph will be better as drag will decrease as the geometry of the hull is improved , I think a prop change is going to have to happen to get the max out of it and keep it at the recommended max rpm's ------- the biggest kick for the buck for improvement I think would be a anti-cav plate , the Edge is my choice
I put a 6' manual jackplate on my 18 ft all. bay boat. the motor is with the cav. plate aprox 1' above the bottom of the boat. I got a better ride and a small increase in top end,but I hardly run my 115 yami 4 stroke wide open mostly around 4000 rpms. What I noticed the most is a better ride. I also have a 14 ft flat with a 40 hp yami with a 4' jackplate this is also raised so I can go in real skinny water, it also has pods no real increase in speed either.
don't think these jackets will help his motor height???

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