Results 1 to 7 of 7
  1. #1
    SCHNORR12's Avatar
    Join Date
    Mar 2012
    Location
    Lake George, NY
    Posts
    834
    +1
    92

    Angry 2008 STX15F - Not running correctly.

    Hello everyone. To make a long story short, I bought a 2008 STX15F about a week ago and since we were going to have a nice day today I decided to take it out on the lake about 20 minutes away. The ski starts right up and does not sound funny when at idle. When I got it on the water today and exited the no wake zone, I slowly pulled the throttle. The ski wouldn't go above 4,000 RPMs. Once or twice it would jolt to 5,000 RPMs and then back to a constant 4,000 RPMs. As for speed, the ski at no point went above 30 MPH. Most of the time it was stuck around 20-23 MPH. I became frustrated (as you could imagine) and headed back for the launch. On the way back, the ski was slowly moving at lower and lower MPH. This is my first ski, and I have no idea what is wrong with it so any help would be greatly appreciated. It did not seem to be throwing any codes and I'm on my way to the auto store right now to get a compression tester. Thanks for the help.


  2. #2
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
    Join Date
    May 2008
    Location
    Houston
    Posts
    4,486
    +1
    320
    Did you make sure you didn't suck something up into the pump? If the ski had sat for a while it could have rusted up the fuel pump, that is fairly common on these skis. Check fuel pressure and look for exhaust leaks.

    Sean

  3. #3
    SCHNORR12's Avatar
    Join Date
    Mar 2012
    Location
    Lake George, NY
    Posts
    834
    +1
    92
    I went to the store to buy a compression tester and spark plug socket and while I was there an acquaintance who is a mechanic at the local dealership answered my text and told me he would stop buy to check it out. We looked at the spark plugs and they looked fine. He took the top of the motor off to make sure there were no metal shavings that would indicate crankshaft issues (which he had seen before on this particular ski). He then took the jet pump apart to inspect the impeller. Everything checked out and we checked the compression, that was fine as well. We hooked the trailer to his truck and headed for the lake because he wanted to ride it. We picked up NGK spark plugs along the way. We put it in the water, he rode it, it did the same thing as when I rode it, he swapped the spark plugs, and rode it again. It seems as though the spark plugs were the issue because the ski now performs as expected.

  4. #4
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
    Join Date
    May 2008
    Location
    Houston
    Posts
    4,486
    +1
    320
    check the fuel pressure anyways, its not difficult to do and it could save your motor. Also be sure to put antisize on the threads if you have not already, its really easy to break the plugs off in the head if you don't

    Sean

  5. #5
    SCHNORR12's Avatar
    Join Date
    Mar 2012
    Location
    Lake George, NY
    Posts
    834
    +1
    92
    How do you check the fuel pressure?

  6. #6

    Join Date
    Aug 2009
    Location
    Shuswap lake, Canada
    Posts
    170
    +1
    3
    When my 12f lost a plug it acted this way. New plug solved the issue. Ski had 123 hrs on it and I'm pretty sure was using the original plugs.

    Now you know...these engines need plugs from time to time....and I now carry a spare in the kit.

    If you didn't use anti-seize on your plug threads....you better do it soon.....the plugs are easily broken off in the head if the threads get sticky.

  7. #7
    Daveski's Avatar
    Join Date
    Apr 2009
    Location
    Franklin,WI
    Posts
    488
    It was definitly the plugs, My ski did the same thing last year, took out the original plugs, all looked real good, put in new set of plugs, ran perfect.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2011 RXT-260 not running correctly
    By craig41071 in forum 4-Tec Performance
    Replies: 3
    Last Post: 09-09-2013, 01:22 PM
  2. FS 80mps+ 2008 RXPX 4000 OBO not running
    By t_hoang02 in forum Sea Doo 4Tec Skis
    Replies: 4
    Last Post: 04-17-2012, 11:32 AM
  3. Replies: 6
    Last Post: 11-26-2010, 01:09 PM
  4. Genesis i not running correctly
    By metriclips in forum Polaris Open Discussion
    Replies: 5
    Last Post: 10-15-2009, 07:52 PM
  5. Not running correctly
    By darrel in forum 4-Tec Performance
    Replies: 4
    Last Post: 07-27-2009, 10:59 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
  •