Reply To: Johnson AD-12 7.5 HP Piston Ring End Gap etc.

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February 14, 2021 at 8:02 am #230523
Don
Participant

    US Member

    The ring end gap spec for your 7.5hp is: .007-017″. Something is wrong if new OEM rings need “filing”, wrong part number, improperly bored oversize, etc. Again, I am referring to OEM rings, follow whatever instructions are included with aftermarket rings.
    I would not use any type of piston ring compressor on this engine, you don’t want to chance misaligning the rings over the piston alignment pins. I would just use my fingers to compress the rings on this little engine, perhaps with the help of an assistant, I’m available (on vacation) next week….D