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  1. #1

    96 slt 780 running wrong

    i recently bought this ski and it isn't running quite right. this is my first ski so I'm by no means an expert but i know enough about engines. my problem is the ski boggs down and will only top out at maybe 25miles per hour. it then runs like thats its top speed like not spitting and sputtering unless you turn fast or when you accelerate. i checked the plugs and they were all warm telling me it was firing on all cylinders but when popped the plugs the third cylinder had a fair amount of gas in it. which led me to believe the float was stuck in the carb and it was dumping gas in and then only running on 2 cylinders. so i pulled and cleaned the carbs really well and got all the gas out of the motor. i then put the carbs back on and same exact problem. am i over looking something? any help would be greatly appreciated guys. can not figure this out.

  2. #2
    def's Avatar
    Join Date
    Jan 2014
    oshawa, ontario
    you found the right site bowfisher19 - I just got one of those this winter and with the active help here I was able to get it quickly fixed. There is a load of tutorials and super helpful people here. Sorry i dont have more to contribute - my issue was stator and cdi fried.

  3. #3
    BlueFishCrisis's Avatar
    Join Date
    Aug 2011
    Medina, Ohio, United States
    What are your compression numbers on each cylinder? Have you tested the electrical stator yet?

  4. #4
    Sorry it took me so long to reply. I am
    even more confused now if you can believe that. I found out one of the plugs had a crack in it and wasn't firing. So I got 3 brand new ones hoping that would fix my problem. The problem now is the first cylinder does not seem to be running. I ran it around the lake and would only top out at 30mph. Like top speed not bogging or anything got back to the house and shot the cylinders with a temp gun. The first cylinder was 15degrees colder and the plug didn't seem to be burning. I checked all three with an inline spark checker and had good spark on all 3. Compression was 125 across all 3. What is going on? I've heard of a limp mode? What is that? Could that be it? Help!

  5. #5
    Limp mode will limit your ski to 4200 rpms, then it hits a "rev limiter" it seems like. You can bypass it by unhooking the gray wire coming from the cdi in the electrical box

  6. #6
    Is there anything special I need to do with the wire? Or just unhook it an let it be. Is that all it controls?

  7. #7

    Join Date
    Aug 2006
    Homer Glen Il.
    just unhook it

  8. #8
    The gray wire is already unhooked. Everything seems to be in order. It will only go 30mph and it doesn't seem like the first cylinder is constantly firing. It is colder than the others but is not full of gas when I pull the plug. Any ideas what the problem may be?

  9. #9
    def's Avatar
    Join Date
    Jan 2014
    oshawa, ontario
    hows the MFD on your unit? mine got some moisture in it this weekend and it caused my machine to run wierd. I ended up disconnecting the MFD and the machine ran just great. Im having issue with my fuel level sensor so i am figureing the limpmode thing is what it was doing.

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