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  1. #1
    Tony's Avatar
    Join Date
    May 2007
    North Carolina

    What's this hole for?

    Picked up this OEM piston kit to replace one on my '97 1050. Here's a picture of it next to the one that it will replace.

    I have a '98 1050 that I'm tearing down now and noticed it didn't have this hole/port on the piston.

    So, what's it for and why doesn't the '98 have it? Is the difference because the '97 is running 009 cylinders and the '98 has 081's?
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  2. #2

    Join Date
    Apr 2006
    panama city beach 'fl


    holes for boost port also help cooling ether will work fine
    polaris was allways changing stuff midway thur years

    later cd

  3. #3
    casey67's Avatar
    Join Date
    Sep 2006
    I was told the hole helped cool the top of the piston.The 009 cylinder I know has a hole in the cylinder wall just below the boost port to match the piston.009 cyl was replaced by 018 ,which does not have the hole in the cyl wall.I suspect the 081 cyl should also have it.I know the newest piston # from Polaris(2201626)does not have the hole.not sure when Polaris used this piston in production.
    I don't know how or if it affects how it runs.

  4. #4
    Watcon's Avatar
    Join Date
    Oct 2005
    Seattle WA

    Chip is correct..

    I agree with Chip, and I have used/ added/ removed holes in pistons many times.. I think it helped keep the top (underside) of the piston cooler, and we did it for some high compression motors.. But I wouldn't worry about it either way.

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