Results 1 to 6 of 6
  1. #1
    Join Date
    May 2012

    2011 ultra 300 - head scratcher

    Customers ski has been running fine. Suddenly it wouldn't much over 52-54. Changed plugs, no diff. Removed exhaust to check filter, it was missing and plugged the waterbox like a cork. Luckily, finally got that out and installed a new filter. I assumed this was the issue. Took it for a spin.
    Here's what happens - under easy acceleration from a stop, it hits 52-54. Boost is showing full. If I accelerate full throttle from a stop, get the rpms up quick from slight cavitation, she'll rip like it should up to 64/65 or so. Come to a stop, accelerate slowly...back to 52/54. Rpm around 68-7g. Back to a stop, full throttle out of the hole and speed and rpm back to where it belongs. Hoses tight, no water in hull, s.c. belt appears fine. No belt residue, feels tight and boost gauge is up. Compression fine, took fuel samples(couple cycles worth from inlet hose) and appers perfect. Scratching my head. Next I was going to run a fuel pressure check, unless something else solves this. Thanks.
    Last edited by jimfleming88; 11-03-2022 at 09:32 PM.

  2. +1 by:

  3. #2
    Myself's Avatar
    Join Date
    May 2007
    North Central Arkansas
    I had one last year acting similar. It had some water in the gas.

  4. +1 by:

  5. #3

    Join Date
    Jul 2019
    Coppell, Texas
    My 2011 is doing something similar. I have two identical machines. One is fine the other is the problem. The supercharger tensionser was frozen; fixed that, but didn't fix the probelm. Gas is clean (no water). Spark plugs gapped and clean. Fuel pressure is good. Going to check the exhaust filter next, but really don't think that is the problem. Did you ever find out what was going on with the one you were working on?

  6. +1 by:

  7. #4

    Join Date
    May 2008
    I'd agree that it doesn't make sense per the symptoms, but with these engines along with a compression test I do a leakdown. I've found the boost really beats on the rings a bit and you see odd issues.

  8. #5
    A bad speed sensor could do it.. ECU limits speed based on the sensor.

  9. #6
    For what it's worth, I also have two 2011 300 ultra LXs and most of the time it's spark plugs. This is especially true if the ski hasn't been ridden very much.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2011-12 ultra 300 ECU work correctly on a 2013 ultra 300?
    By jetdave56 in forum Kawasaki PWC Performance (4-stroke)
    Replies: 13
    Last Post: 06-19-2014, 03:37 AM
  2. FS - Parts Parting out 2011 ultra 300
    By STEVE PWC in forum Kawasaki Classifieds
    Replies: 22
    Last Post: 10-24-2013, 06:59 PM
  3. 2011 Ultra 300 vs 2013 Ultra 300 any difference in models
    By pierstar in forum Kawasaki PWC Performance (4-stroke)
    Replies: 1
    Last Post: 07-09-2013, 12:11 AM
  4. Took my new 2011 STX-15F and 2011 Ultra 300 LX out for the first time this year
    By Fiftydriver in forum Kawasaki PWC Performance (4-stroke)
    Replies: 2
    Last Post: 06-08-2013, 02:46 PM
  5. FS - Parts Parting out 2011 ultra 300
    By STEVE PWC in forum Kawasaki Classifieds
    Replies: 0
    Last Post: 12-03-2012, 10:01 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