Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: setup questions

  1. #1
    tahitijet
    Ok I took the boat out today for the first time after adding a split bowl, droop, ride plate and 2* wedge.. I spoke with Jack at MPD who gave me some pointers for setting a starting point on the rideplate and wedge. I ended up at 2* up wedge and I think (I don't remember off hand) at 5* up in relation to the keel on the ride plate
    The bottom has been blueprinted and pump setback as well as a backcut shoe. It was a bit hard to tell as the water wasn't to good but here is what i noticed.
    First thing i noticed was the boat had a whole lot more bow rise and took much longer to get on plane.. Is this typical with a droop? This was with the diverter in full down.
    There seemed to be alot of feedback (left hand preasure) on the steering wheel like something on the diverter was dragging and making me put right imput in the wheel to stay straight. What is causing this?
    Before these changes the boat had a mild porpoise above 70mph that could be tuned out by the diverter.. Now it has a low speed porpoise that you can't fully get rid of even with full down diverter.
    Anyone have any input on these items? I'm assuming I should start by either droping the ride plate or flipping the wedge??? Im thinking either one would help with bow rise and planeing, and at least give me some more down diverter as i'm thinking full up may be way to much up. but i'm thinking that by dropping the plate it might free up the steering?
    just wondering where to start adjusting from here.
    thanks

  2. #2
    Ken F
    I believe I would start by dropping your rideplate to about 2 degrees above keel.
    To me, your low speed porpoise and bowrise would be indicitative of the rideplate being too high. (allowing the boat to "rock" back and forth from the hull to the rideplate.)
    I don't think your 2 degree wedge in your droop is going to cause any of your problems mentioned other than possibly the steering problem. It could be that with the droop you are now dragging your divirter. (?) With the divirter on there, you should be able to overcome/adjust past any thrust angle problem.
    Good luck, I'm sure someone who is a little smarter than I will chime in.
    Ken F

  3. #3
    Taylorman
    Im having the steering pull problem like you. I had someone drive for me this weekend and i looked at the pump. I could not see anything dragging in the water that would cause the steering problem. My boat will turn right if i let go of the steering wheel. I can't figure out whats causing this.
    Kevin

  4. #4
    texas-19
    taylorman,
    If you are looking at the rideplate from the rear,could the plate be lower on the right side than the left.That would cause it to turn right.Try putting an extra washer on the left side of the ride plate under the rear bracket and see what that does.
    Tahitijet,I agree with Ken,sounds like the rideplate is too high but i would lower it 1 degree at a time until i was happy with it.When the bow goes up the nozzle will drag until you are up on plane,and maybe with that much ride plate angle the nozzle is still dragging even on plane.Thats my experience anyway.

  5. #5
    Senior Member
    Join Date
    Apr 2010
    Posts
    2,920
    I'd agree with all that mentioned the rideplate angle being too great and causing the porpoise.
    As for the steering (pulling) issue............Here's what I found with mine this winter when I flipped it over.
    Although the rideplate has holes drilled in it and the bolts fit relatively tight, I found that my rideplate was actually cocked to one side a bit (speaking about the four holes that attach it to the shoe). There's just enough play in the holes that you have to check to make sure the rideplate is square to the back of the shoe (and boat). Mine pulled like a mad mogator until I noticed this and corrected it. I also had to grind a little material off the cradle so I could get the rideplate moved over to where it needed to be. The stiffners were making contact with the cradle before I did this.
    When the boat was on the trailer it was difficult to notice. Now that I know it's like that, I check it for squareness with it's mating surface on the back of the shoe to see if the gap is even all the way across. You'd be surprised as to how much you can move the plate back and forth prior to tightening the hardware down all the way.

  6. #6
    Taylorman
    Thanks Dan, i'll have to check that. Ive been told to stand behind the boat about 20 feet to see if the ride plate is level relative to the boat. It appears to be. Ive not checked for ride plate being square.
    Just to clarify, your ride was pushed left or right, not one side being lower than the other?
    I need to go home and check that.
    So how did you correct the problem? I guess you would have to remove the bolts from the craddle, square the plate to the boat and redrill the craddle holes then tighted the plate to the shoe?

  7. #7
    tahitijet
    thanks for the input guys.. one other thing i noticed was the pull was much harder with the diverter up then down.
    The boat carried the bow higher then usuall so i figured it was something either with the plate or wedge.. I'll try the plate but just curious what effect would flipping the wedge to 2* down would have?
    thanks

  8. #8
    victorfb
    i had that same low speed porpoise when i had the droop with no wedge. i added a 2 degree up wedge which lifted the thrust line and it went away. i used to have to run with the diverter fulldown and dragging to get rid of the porpoise. now with the wedge it rides real nice. if i had a three degree id try it but with my set up now it seems to work real well with the diverter throwing a 2' maybe 3' high roost. my ride plate is set at 4.5 degrees up from keel line which may need to come down a degree. this is an 18' rogers hull and all hulls act differantly to changes and set ups, you just have to play with it. good luck.

  9. #9
    Squirtin Thunder
    I have tried all above, they all had small efects on ride and porpise.I tried the droop with no wedge @ 4* up plate. It took full of down, on the diverter, to get the boat to ride OK. Then put 2* up and it got worse. I tried 2* down wedge then went back to no wedge and less plate up, 3*. I was able to do 1* at a time because of my set-up design, turnbuckles. Still shitty ride at low speed. Put 2* down wedge, 2* up on the plate, abit better. Went with 4* down and 1* up plate, ride is good at low speed and real good in chop. It also pulls like a rapped ape all the way up to top speed now. Lower thrust angle, less squat, means less drag. Also the boat pops up on plate extreamly quick.

  10. #10
    Senior Member
    Join Date
    Apr 2010
    Posts
    2,920
    Thanks Dan, i'll have to check that. Ive been told to stand behind the boat about 20 feet to see if the ride plate is level relative to the boat. It appears to be. Ive not checked for ride plate being square.
    Just to clarify, your ride was pushed left or right, not one side being lower than the other?
    Mine was not one side higher than the other, but angled to the right side of the boat, causing the boat to pull left HARD.
    So how did you correct the problem? I guess you would have to remove the bolts from the craddle, square the plate to the boat and redrill the craddle holes then tighted the plate to the shoe?
    I didn't redrill the holes in the cradle, I just used a die grinder and hogged em out a little (elongated them side to side). I was a little concerned about doing that due to all the pressure on the plate, but it hasn't been an issue. I thought it might be possible for it to shift back to it's original spot, but as long as everything's tight it seems to work out. The adjustment was very small and made a very big difference in handling.
    Like I mentioned earlier, I did have to remove some material from the cradle because the rideplate stiffners would contact the cradle before the plate would line up properly. Just took a 4" grinder to the cradle and removed about 1/8" of material to allow for the lateral adjustment.
    thanks for the input guys.. one other thing i noticed was the pull was much harder with the diverter up then down.
    My symptoms exactly. With full diverter up it would about wrench the steering wheel out of your hands. Amazing how such a small adjustment, can make such a huge difference.

Page 1 of 3 123 LastLast

Similar Threads

  1. a few questions about my setup
    By W.O.T in forum Jet Boats
    Replies: 3
    Last Post: 09-04-2006, 07:56 PM
  2. HELP! Basic Stereo Setup Questions
    By InKahntrol in forum Audio
    Replies: 1
    Last Post: 08-21-2006, 08:53 AM
  3. Cavitation Setup Questions Please Help!!
    By sifocalpoint in forum V-Drives
    Replies: 5
    Last Post: 10-30-2004, 07:05 AM
  4. Setup questions
    By Squirtcha? in forum Jet Boats
    Replies: 6
    Last Post: 11-26-2003, 07:48 PM
  5. Setup Questions
    By e-ticket in forum V-Drives
    Replies: 8
    Last Post: 07-30-2003, 06:11 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •