Results 1 to 3 of 3
  1. #1
    Dave Sharp dav_dman's Avatar
    Join Date
    Aug 2005
    Location
    louisville Ky/so. IN
    Posts
    1,453
    +1
    1

    lowering stock sponsons.. how to?

    i saw a post where guys said lower stock spons 23mm i think for better corning.. I haven't measured but it looks like I only have about 17mm from bottom of spons to hull line.. do you lower then below the hull line?!? (my guess is based on about 2/3 inch space and 1 inch is 25mm).

    also, Any porpoise advantage to stepping the spons like we did the gpr's?


  2. #2
    R88ory RXP's Avatar
    Join Date
    Feb 2008
    Location
    Kent, England
    Posts
    2,737
    +1
    46
    Quote Originally Posted by dav_dman View Post
    i saw a post where guys said lower stock spons 23mm i think for better corning.. I haven't measured but it looks like I only have about 17mm from bottom of spons to hull line.. do you lower then below the hull line?!? (my guess is based on about 2/3 inch space and 1 inch is 25mm).

    also, Any porpoise advantage to stepping the spons like we did the gpr's?
    All you have to do is get everything out of the ski so you can get to the bolts on the back of the sponson. Undo the 10 bolts (5 each side) then pull the sponson off. Clean all the old sealent off and measure 23mm centres down, and drill new holes. Just go down in a straight line no angles or anything. You can go anywhere between 20-25mm the lower you go the more aggresive they are. Mine are 23mm.

    Then with high quality polyurathane adhesive/sealent fill the old holes and re-seal the sponsons onto the hull.

    Yes the back edge hangs down in racing they have to be filed flat to the angled part of the hull.

    Yes this cured the porpoising on my ski. Maybe loses a bit of top speed but for cornering it is hands down the best setup for the rxp platform. R88

  3. #3
    Dave Sharp dav_dman's Avatar
    Join Date
    Aug 2005
    Location
    louisville Ky/so. IN
    Posts
    1,453
    +1
    1
    yeah, you're the guy! thanks for the response!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Lowering stock sponsons question
    By KNOURROL in forum 4-Tec Performance
    Replies: 5
    Last Post: 07-29-2012, 02:56 PM
  2. Lowering stock sponsons
    By tris in forum 4-Tec Performance
    Replies: 4
    Last Post: 05-01-2011, 08:43 PM
  3. How to tell an SBT engine from a stock yamaha engine? (1200 non-pv)
    By jcc011185 in forum Yamaha Open Discussion
    Replies: 10
    Last Post: 07-22-2007, 09:15 AM
  4. Anybody Know How To Remove Sponson Bolts
    By yellow4 in forum 4-Tec Performance
    Replies: 2
    Last Post: 07-19-2007, 10:25 PM
  5. How to?? Sponsons
    By RedlineR6 in forum Polaris Open Discussion
    Replies: 10
    Last Post: 03-08-2007, 06:05 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
  •