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  1. #1

    Cold seizures 97 GP760

    Hello everyone. First time post here. I was referred to this site by one of your members. Hoping I can get some answers on this issue. I picked up this machine cheap due to low compression on the front cylinder. I've never worked on a PWC till this one. However I've rebuilt tons of Atvs and snowmobiles. I tore it down and I had it bored over with wiseco pistons. The clearance was put at wherever wiseco recommend. I don't remember off hand what that was. I want to say it was .005. I may be wrong. Atv's are always.002. I set the carb jets to factory when I put it back together. First time out last year it kept cold seizing when it was put at full throttle. It abruptly shut off. But it would start right back up. This happened about 8 times that day. So we didn't go full throttle for the rest of the day. I checked compression and the grimy cylinder dropped about 30 psi from when it was fresh.
    When I put it back together I checked for crank play, rod play. All was good. None of my coolant or oil lines came off. I talked with a tech last year and he said never use forged, always cast pistons.
    Think my issue is the carb going lean at WOT?


  2. #2
    ncdoo's Avatar
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    Wiseco's require at least .007 clearance. More than most other pistons. With that said, make sure you warm it up well each time.

  3. #3

    Join Date
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    If clearances are in range, then carbs/fuel delivery are probably an issue. Could be the pickup is gunked up, hoses are deteriorating and collapsing, the vent to the gas tank is not working, the carb filters are dirty, the needle and seat are bad or have debris in them, there could be an air leak in the intake or the engine crank seals could be leaking, a multitude of potential causes. This ski is 22 years old and you do not know the history. There are many things you can check with information in the How-To section.

    PS: forged pistons are fine in these boats, especially when modified. I have done many without issues (that were not caused by other things, not the piston fit).

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