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  1. #1

    GP 800 Problems Please Help

    I really need a manual for the GP800. I am not sure why it runs like crap. I bought the ski with the top end needing to be redone. Did that plus cleaned and rebuilt carbs. Checked pop off etc. basically whats happening is the ski starts, idles rough and pops and cracks then backfires out the exhaust side(i know this because it backfires so bad that it actually blows a flame past the gasket at the header. At first thought maybe it wasnt sealed there but about after the 15th time i took it apart i put RTV silicone on it to make sure. Same result. I have spark at both cylinders and descent compression. I have no idea what i am doing wrong. The only thing i can figure is timing which i have no idea how to check, Improper fuel(which i would have no idea why its not working because i have been through the carbs 3 times) or the other possibility could be a hole in the crank case that i cant see someplace from when the piston broke. also the reed valves seem to be ok. If anyone has any ideas please help me!


  2. #2
    Malarkie's Avatar
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  3. #3
    timing is static on these. mag cup is fixed to a flywheel and it has a stationary trigger. the fly wheel may be on wrong. I had one shear a key. took me a while to figure it out. did you do the top end or did a shop do it? it could be a bad pick up. if you look on this site you will find shop manual and it will tell you how to trouble shoot the ignition system. Yami shop manuals are very good.

  4. #4
    i did it my self. I have been racing bikes my whole life and can rebuild a two stroke motor with my eyes closed. I have been working on alot of skis lately trying to learn, I just am not up to speed (yet) on my jet ski electrical sytems. i figured it was static timing but didnt know for sure. i need to check the key on the wheel for sure. Its possible that happened. I also need to check the pickup . It seems like it almost has to be some sort of timing issue. I really need to hunt down the manual, just cant seem to find one.

  5. #5
    Mongoose's Avatar
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    Quote Originally Posted by myersmotorsports View Post
    i did it my self. I have been racing bikes my whole life and can rebuild a two stroke motor with my eyes closed. I have been working on alot of skis lately trying to learn, I just am not up to speed (yet) on my jet ski electrical sytems. i figured it was static timing but didnt know for sure. i need to check the key on the wheel for sure. Its possible that happened. I also need to check the pickup . It seems like it almost has to be some sort of timing issue. I really need to hunt down the manual, just cant seem to find one.
    Email me [email protected] -got something that may help you

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