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  1. #1

    What oversize should my 650 have?

    I am looking for new pistons to my 650 sx. The former owned changed the cylinder width to 77mm from 74mm.
    Should I go for 1mm oversize pistons or 1,5mm?

  2. #2
    I thought I would buy from a close store, but can anyone point out which ones would be best for me?
    The 77mm exactly or one size down (76,75mm)?

    Am I getting it wrong? How should I understand this piston size and then the width of the piston? Is it two different things?

  3. #3
    steve45's Avatar
    Join Date
    Feb 2008
    I don't know how much larger you can go. Normally, you want the smallest oversize so you can re-bore the cylinders in the future. Are you trying to fix a scoring problem, or trying to get more displacement. The increase in displacement isn't worth the effort, in my opinion.

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