Jack plate=confused. Please help

[M80]

I've got a 84 stratos, 18 ft with 150 mercury. 6" jack plate and have run the boat it's whole life the way it was set up till a year ago. Someone told me if I raised the motor it would help the performance of the boat and make it ride higher out of the water. What I've noticed is it actually runs lower in the water after raising it 2". The water pressure loses a couple pds of pressure but still around 18. I've read and read about this and really can't find my answer. I know I can't go any higher cause my pressure is already starting to drop, but what is funny is that the differance from my pad and center line of prop is 4 1/2 " below the pad already. I don't care about speed but my boat is rising high enough out of the water. It sprays water out the side right at the console on both sides. I can hit my trailer button on the trim and it will start lifting the boat higher out of the water but pressure starts dropping. I know weight makes a big differance on boats already.

Question is if I lower my motor which will make the pad from centerline more like 6" will it cause my boat to ride higher out of the water. I've sit and studied looking at the set up and can't help but think it has got to if the motor comes up to the same place when lifted on plane.

One more thing is people say the cavitation fin should be even with the pad or a 1" high with the boat level and motor trimmed down level. Mine is 4" above the pad. So I think my motor is running to high out of the water. What do y'all think

Sorry for long post and thanks for input

 

[TroyBoy30]

riding higher in the water has nothing to do with it. you want to adjust the height on the plate in 1/4 in increments until you either get no more speed and an rpm increase or your water pressure gets below 12-15

go to the stratos section of bass boat central. they can give you a general starting point for prop to pad height and proper prop pitch

 

[tllewis]

Troy just gave you spot on advise.

 

[M80]

So if my prop isn't getting a good bite and I lower it a little can it lift my boat a little more. I'm using a 24 pitch prop, 3 blade stainless steel

 

[tllewis]

www.bassboatcentral
Go to Stratos boat section or I think there is a section dedicated to set ups. I promise you, you will get the answers your looking for there. Best resource I've ever found.

 

[pbmang]

I can hit my trailer button on the trim and it will start lifting the boat higher out of the water but pressure starts dropping. I know weight makes a big differance on boats already.

This makes me scratch my head a bit, but could also explain a bunch. When you say you hit the trailer button, do you mean you are just trimming the motor up? When you are running, after the boat gets on pad, you do need to trim the motor up to raise the boat up and get more speed. There will be a point where your speed will stop increasing, and just below that is where you want to run your trim in most cases. That is also the point you want to check your RPM's and water pressure, then adjust your jack plate according to that. On BBC they will ask for your prop to pad measurement, max RPM's and water pressure, and they are looking for the RPM and water pressure numbers once the boat is on pad and trimmed out.

Hopefully that makes sense!

 

[M80]

It does. I run my boat trimmed all the way up and it still sprays out in front of drivers seat. So I then hit the trailing button to raise it more and just when it starts picking me up out of the water where it feels right my water pressure starts dropping. I'm going to lower it about 1 1/2 inches so I get more water pressure and then when I hit my trailering button to get more trim I should keep good water pressure. I guess the boat is to old and weighs to much

 

[pbmang]

I haven't heard of a trailering button. Does it just allow you to trim the motor up more?

 

[tllewis]

Yes, Chris. My old Merc. controls are the same. I wouldn't think you would ever want to trim higher than the dedicated trim button would allow. The trailering button he speaks of is just to raise the motor high enough to put your motor toter in place.

 

[M80]

Well I lowered it and it didn't help. Lots about three mile an hour. I think I will go up a little higher than I had it. I probably need to drop to a 23 pitch prop. It was kinda hard to tell if it helped a lot cause we had 18.02 pounds of bass and I had to use the front live well too I'm going to play a little more with it. Thanks for y'all's help.

 

[Gunny146]

Bring her down to Oconee or Sinclair one day and I'll give you a hand. It can take a whole day to get one set up right. I finally got mine where a 115 would push my F/S 50 on GPS.

 

[M80]

Bring her down to Oconee or Sinclair one day and I'll give you a hand. It can take a whole day to get one set up right. I finally got mine where a 115 would push my F/S 50 on GPS.

Thanks brother. I'm borrowing a 23 pitch prop and going back up with it. If I can't get it figured all out I might take you up on your offer