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  1. #1

    Join Date
    Jun 2015
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    Kingfisher, OK
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    89

    00 GP1200r rebuild

    Got my first jet skis, a 99 GP800 and 00 GP1200r. Did a pressure test on both and the GP1200r had low psi on first cylinder. Got 110 on rear, 113 middle and 80 psi on front piston. Currently in the process of tearing into it and i figured i would start a thread since i will need a little guidance along the way. For starters i need a source for good parts at a fair price that i can get all the gaskets and such for fixing the cylinder. Im also looking for suggestions on other things to look at that are known problems.

    Thanks
    Last edited by txredxj; 06-11-2015 at 11:15 AM.


  2. #2

    Join Date
    Jun 2015
    Location
    Kingfisher, OK
    Posts
    89
    So after reading late into the night looks like crank seals, cleaning carbs and power valves, d plate and oiler system are things I need to do or check. Anybody got good links or keywords to search with about cleaning the carbs and power valves? Can I pressure test the engine to varify the crank seals are good? Got 81 hours on the clock.
    Last edited by txredxj; 06-11-2015 at 09:23 AM.

  3. #3
    Quote Originally Posted by txredxj View Post
    So after reading late into the night looks like crank seals, cleaning carbs and power valves, d plate and oiler system are things I need to do or check. Anybody got good links or keywords to search with about cleaning the carbs and power valves? Can I pressure test the engine to varify the crank seals are good? Got 81 hours on the clock.
    Look in the FAQ's. There's a test thread there.

    If its its got those comp numbers and you want it to last, and have the cash...I'd tear it all down and start from a good baseline

  4. #4

    Join Date
    Jun 2015
    Location
    Kingfisher, OK
    Posts
    89
    Are those low numbers for a stock engine?

  5. #5
    If you did the test right, yes. 110-113 is low, 120-125 is stock compression I believe. But the 80/psi is not good.

    You held the throttle wide open. Good battery. One plug out at a time?

  6. #6

    Join Date
    Jun 2015
    Location
    Kingfisher, OK
    Posts
    89
    I had all the plugs out when I did it. Battery was dead so I had it hooked up to my truck with heavy jumper cables and throttle wide open when I cranked it. I have only worked on single cylinder gas 2strokes so I didn't know about keeping the other plugs in. I will redo it with the plugs in and see what I get.

  7. #7

    Join Date
    Jun 2015
    Location
    Kingfisher, OK
    Posts
    89
    Came out a couple psi over first test.

  8. #8

    Join Date
    Jun 2015
    Location
    Kingfisher, OK
    Posts
    89
    Got it torn down and found more then i thought. First problem the bottom bracket for the cat housing had a tab broken off. Looking in at the cat element it had broken out and was blocking the exhaust. Not a big deal since i can weld the aluminum bracket and was planning on a d plate anyways. Moved on and got the head off and it looked like cylinder #1 was lean. Inspected the other cylinders and #3 had the top edge of the piston bent up by the power valve. Roll it over to check the power valve and its GONE! Looks like it was lost when they stopped riding it because the hole it sets in was nice and shiny.

    #1


    #2


    #3 piston lip bent


    #3 power valve gone

  9. #9
    Errrrr.
    What's you're plan?

  10. #10
    How many hours?

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