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  • David C

    Replies: 1
    Topics: 4

    need some help on my 1937 ob12a neptune.Got it back together have spark and gas but it wont fiire.50 to 55 psi is all i can get after honing cylinder? Rings feel sharp? Thanks Dave R

    The Boat House

    Replies: 3514
    Topics: 88

    That is too low.
    Did it run before you honed the cylinder?
    Why did you hone the cylinder?
    What was the compression before you honed the cylinder.
    Honing a cylinder and putting the old rings
    back in only lowers the compression as the
    rings are no longer seated.


    You're only as smart as the person you're talking to.


    US Member - 2 Years
    Replies: 189
    Topics: 15

    Remove magneto and spark plug. Squirt oil into carb and spark plug hole. Hook an electric drill to the nut on the crankshaft. Turn the motor over with the drill for 5-10 minutes, making sure you squirt oil into the spark plug hole and carb occasionally. This should help reseat the rings. If this don’t help improve compression, check ring gap and ring side clearance.

    • This reply was modified 1 month, 2 weeks ago by jcrigan.
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