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  1. #1

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    1997 760GP, wont start, help with possibilities?

    Hey there! been trying to get my 760GP going for a while now, i think it's a carb issue. trying to get list to look for made, heres what i have.
    -no fuel from carbs spraying
    -good impulse lines, strength of suction
    -carbs fill with fuel, fuel seems to come through lines
    -saw needles had a little groove worn, ordered some w seats
    -cleaned filters, orfices, blew carb clean through jets, feed and return ports
    40psi pop off bothcarbs

    possibilities,
    -low speed screw needs to be turned out?
    -needles are sticking?
    -check valves backwards?
    -clogged fuel select switch?

    could use ideas guys. thanks
    Last edited by nickmm; 06-15-2013 at 07:57 AM.


  2. #2
    Yamaha artisan Cutlass's Avatar
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    does it start if you pour a little gas down the carbs?

  3. #3

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    it popped but wouldn't stay running. certainly tried to fire though

  4. #4
    Yamaha artisan Cutlass's Avatar
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    have you checked the compression? Its definitely a possibility for your problem.

  5. #5

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    not yet, i haven't a gauge. pistons or reeds could cause this?

  6. #6

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    tried it again today, put fuel right in the plug holes and got nothing. pretty much seals the deal on compression, huh? i suspect the previous owner ethered it to death. i checked spark with a tester, seemed strong. now i think the battery was a little dead, so I'll charge it and try one last time.

    is it worth new pistons, crank seals and all that? it is in very nice shape otherwise.

    maybe try a lighter version of what Mac did here:
    http://www.macdizzy.com/gp.htm

  7. #7
    Yamaha artisan Cutlass's Avatar
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    First things first, check the compression.
    If its worth it to you, its worth it. It'll probably cost more then the ski is worth so it'll have to be a labor of love. Or just rebuild the carbs/fuel system and throw a SBT engine it.

  8. #8

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    checked compression, removed head, boy I'm lucky, i have a super rare ventilated piston model.

    haaaa. 40 or so compression. but in pulling the head its now obvious, chip right down to the ringland...

    good news, the cylinders are in good shape. I'm going to take it apart Thursday, get cylinders checked out, then start mapping my Ports and see what we got. nothing crazy, but i can already see some bad mismatching, may as well.

    got a line on pistons and a head, just need to verify my bore first.

    $400 or less is my goal, we shall see..
    Last edited by nickmm; 06-23-2013 at 04:10 PM.

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