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  1. #1

    Join Date
    Mar 2019

    Polaris 780 top end rebuild

    Hey guys, I'm currently rebuilding a top end on a SLT 780. Just wondering if you guys have any tips for me or any experiences that you guys would share, since this is my first time doing it. Im also wondering where would you guys recommend buying circlips or c clips whatever you call them. I'm buying some new needle bearings and piston rings. Thanks guys!

  2. #2

    Join Date
    Sep 2015
    Nova Scotia, Canada
    It might be better to buy new pistons that come with bearings, rings and clips, or maybe a complete top end kit if your cylinders are not perfect. A top end kit would also come with all the gaskets for the top end.

  3. #3

    Join Date
    Aug 2007
    Biggest mistakes that lead to engine failure:

    Wrist pin clip gap needs to be pointing up or down, not to the side. They can open up and escape and get into the cylinder wall from the force of gravity.

    Piston rings have a top and bottom, it will say in very small words which side is up.

    Make sure to apply a lot of two stroke oil to wrist pin, wrist pin bearing, cylinder walls, and rings before putting back together. Make sure it's all lubed up from the start and not running with metal on metal before the fuel/oil mixture can lubricate it properly.

    Make sure gasket surfaces are as clean as possible without leaving any gouges in the cases or cylinders. If any air gets into to engine from the base gaskets you will have a lean condition.

    Don't drop anything into the crank case. Not good!

  4. #4

    Join Date
    Mar 2019
    Thank you guys so much for the help! I already have three good pistons, so I will keep searching for the circlips. Hopefully I can find the proper ones! Thanks again

  5. #5 much for the 780? stimpsonjcat's Avatar
    Join Date
    Apr 2012
    Georgia - Lake Lanier - near 6TH

    But call them if you just want the cheap parts, they have them.

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