Results 1 to 9 of 9
  1. #1

    94 SL650/SL750 Performance ??

    Hello all, Sorry but it seems like it has been a year since I posted anything.

    First and Foremost---THANK YOU ALL!!! This site has been a life (and piston) saver. The information and help and suppliers provided by this site is top notch and really I just cannot say enough good things about this forum. Plain and simple this is a Polaris PWC owners saviour.

    I have two ski's both SL650s but one has a transplanted SL750 motor. Both have the fuel system and carburator service done to them and compared to when I got them, they run great!!. But........

    I just got the 750 done and put in the ski. This had truely been a poormans build with ebay parts a plenty. Anyway, I got the 750 all finished, primed, tried to start-no fire. Freakin ebay 750 CDI unit is a POS. I put the 650 CDI unit in and the ski started right up. Looking at the specs I see that I need a 750 CDI to get the ignition advance and RPMs where they need to be. Ok, that will happen but....I couldn't wait I had to hit the water on that beautiful 92 degree day (In PA in April hell yes!!!!!). The ski ran good, still need do some carb tweeking--no WOT runs allowed-yet.

    OK anyway here is the thing. On the 650 when you come out of the hole, the motor comes up to speed but the ski kinda wallows around in the water before it gets on plane then it goes. The motor does not sound like it is "bogging" it sounds like the pump just isn't doing it's thing. I have had two different pumps (looks like the same impeller) and both act the same. Has anyone had any luck changing to a different impeller to get the ski out of the water better? The 750 literally jumps up onto the water. It runs a completly different impeller than the 650 (3 blade not 4) and really just seems like a different ski.

    Wadda think??


  2. #2
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    Welcome back Yes the Impeller will make a difference. Also the impeller clearance will also effect performance.

  3. #3
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    I think you may need to re-silicone the pump shoe to the hull.

    What you're describing sounds like cavatation. Mine did a similar symptom on my 94 650.

    The factory didn't do a great seal job back then. This may be just the ticket for you.

    You'll need to pry the pump shoe off with a long 2x4 and scrape it clean.

    Then re-silicone the pump shoe back on and tighten the jet pump until it cures.

    Unfortunately, you SHOULD check engine alignment after removing the wear ring from the hull to be sure.

  4. #4
    Thanks Beerdart and xlnt.

    Any suggestions on the impeller? Solas, Nu jet ??

    Xlint-you said take the shoe off the hull. Sorry to seam like an ass but HUH??? What is the shoe?

    you mean like the whole intake portion?

    I have replaced and sealed the ride plate.

    Thanks again.

  5. #5
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    Item #2 is the shoe.

  6. #6
    Thanks just looked over the service manual.

    I will give that a try.

    I also just found out I put a '93 pump on the 750. Crap

  7. #7
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    What are you looking to gain? Accel or top speed

    Nu Jet for top speed.

    Skat Trak for accel

    Solas I don't know much about.

    Thanks for the pic Beer.

    Remove the jet pump from the hull.

    Then slip a 2x4 into the pump shoe (#2 in pic)

    Pry down until it comes off.

    Scrape the silicone off the hull and shoe.

    Apply a GOOD quality MARINE silicone to the hull.

    Reinstall the shoe and bolt the pump back into place. (or at least the wear ring)

    Clean off any excess silicone from the "tunnel". (intake)

    Get that 93 jet pump off of there. Get yourself a 94 and newer pump. A long pump will do even better. Plus, add a SS 6 vane stator for even more top speed.

  8. #8
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,574
    +1
    1,272
    Quote Originally Posted by xlint89 View Post
    ...Remove the jet pump from the hull.

    Then slip a 2x4 into the pump shoe (#2 in pic)

    Pry down until it comes off.

    ...Reinstall the shoe and bolt the pump back into place. (or at least the wear ring)...
    Doesn't the ride plate need to come off before the pump shoe?

  9. #9
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    Yep

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 94 SL650 The "General" Let the project begin...
    By Rodneyae in forum Polaris Projects
    Replies: 370
    Last Post: 03-29-2011, 10:16 PM
  2. Her ride: '94 SL650 converted to 750
    By xlint89 in forum Polaris Projects
    Replies: 94
    Last Post: 11-23-2009, 12:23 AM
  3. 94 SL650 vent tube on top of hull, where the other end go?
    By sparky0114 in forum Polaris Open Discussion
    Replies: 3
    Last Post: 05-06-2008, 06:05 PM
  4. 94 SL650 Tuning problem
    By jej001 in forum Polaris How To & FAQs
    Replies: 9
    Last Post: 04-14-2008, 10:21 PM
  5. Installing Block off Kit on 94 SL650
    By davidparise in forum Polaris How To & FAQs
    Replies: 3
    Last Post: 08-17-2007, 07:51 AM

Posting Permissions

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