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  1. #1
    CHICKA WAH WAH bren's Avatar
    Join Date
    Sep 2007
    Cairns, Australia

    kawi flat top help


    need some help with my kawi flat top setup.

    was told they were KX500 pistons, upon delivery of a new set, the pins on the KX500 pistons are a 19mm diameter, the pins on existing flat tops are 22mm diameter.

    I have sent them to kawasaki joy

    Have tried to catch up with Bo Dupreist but number not in service.

    I have cut new domes, re ported and re ground gas valves so really want to stay with this setup.

    anyone have any thoughts?


  2. #2
    Luis Marine's Avatar
    Join Date
    Oct 2007
    Puerto Rico Drag island
    Boring the pin hole to 22mm I have done this before.

  3. #3
    CHICKA WAH WAH bren's Avatar
    Join Date
    Sep 2007
    Cairns, Australia
    thanks for the reply but really don't want to go that way, pistons are ART and they have not been bored to the 22mm, so theres got to be a match somewhere. we only get the catalogue for europe / australia pistons.

    85.86mm bore in a 1352 motor.

  4. #4
    kham383's Avatar
    Join Date
    Jun 2008
    Gold Coast Australia
    The listings on the KX500 prox pistons are 85.94mm A & 85.95mm B, i think all KX500 pistons are 19mm pins thats why some people used to change the rods to suit the 19mm pins & wiseco say from 1988-04 86mm to 88mm in .50 increments. If your bore is 85.86mm then i dont think they were KX500 pistons.
    Measure the pin boss area against your old pistons to see if there is enough material to be able to machine to 22mm & cut a new circlip land any good machinist should be able to do this.
    If you dont want to do that, measure all the distances of your old piston especially where the position of the ring pins are and email prox the info & see what they can do for you.
    here's a couple of links if you havent seen them already that might help /
    Are these 90mm sleeves. Good luck let me know what you find out.

  5. #5

    Join Date
    Jan 2006
    Long time ago there used to be a conversion for MX motor that had the same issue using a Kawa piston. In that they used loose rollers of plus 1.5mm of the Yam small end bearing and the washers will keep them in. They were a total pain installing them as you have to use grease to hold them to the con rod prior to pushing the pin in. ie no cage. Those engs used to rev to 10,000 and was OK in them.

    Also the small end bearing only moves in a arc so less strain than the bigend.

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