Neptune Outboard afraid of water

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    dave-bernard

    US Member - 2 Years
    Replies: 1188
    Topics: 15
    #13460

    IF YOU think it is crankcase leak or seals double up on the oil and try. if there is an improvement then you are on the right trail.

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    garry-in-michigan

    Lifetime Member
    Replies: 3567
    Topics: 31
    #13473

    Many Antique outboard manufacturers specified 40 weight non-detergent oil in there motors. This gave them better crankcase sealing – It’s worth a try …

    . . . . . . 😉

    Buccaneer
    Buccaneer

    US Member - 1 Year
    Replies: 4068
    Topics: 980
    #13494

    Well, I doubled the oil mix on the Neptune and fired it up in the
    test barrel, and learned a few things!
    #1- I’m an idiot (Yesterday when I thought the throttle valve was closed, it was wide open)
    #2 – When running an outboard with a 5:1 fuel mixture, the wind always switched directions,
    blowing Chinese like smog in your face!
    #3 – The throttle keeps working itself open if your hand isn’t on the grip. (is there suppose
    to be a spring on these twins to prevent that?
    #4 – The exhaust noise is objectionable after 20 minutes, when there’s no exhaust tube attached.
    All said it done, it ran for twenty minutes without dying. I wouldn’t can it "smooth", but
    it did idle down fair. Without a prop on, I couldn’t really do any "high speed" tuning.
    I may recheck the compression for kicks to see if it’s come up any from 60 psi, after
    it’s total of 25 minutes running. I’ll put the exhaust tube and prop back on and try again
    when it gets nicer out. Twenty mile an hour wind and in the thirties is not my idea
    of fun. The Neptune did pump water nice, and cylinders ran cool to the touch, but
    of course my test tank had 1/8" of ice on it this morning!

    Prepare to be boarded!

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    dave-bernard

    US Member - 2 Years
    Replies: 1188
    Topics: 15
    #13497

    great job.

    RICHARD A. WHITE
    RICHARD A. WHITE

    US Member - 2 Years
    Replies: 1759
    Topics: 136
    #13498

    Awesome, looks like your on the right track…

    http://www.richardsoutboardtools.com
    classicomctools@gmail.com

    Steve A W
    Steve A W

    US Member - 2 Years
    Replies: 680
    Topics: 46
    #13502

    Buccaneer
    Congrats and Good Luck!
    What part of the country are You from?

    Steve A W

    Member of the MOB chapter.
    I live in Northwest Indiana

    Buccaneer
    Buccaneer

    US Member - 1 Year
    Replies: 4068
    Topics: 980
    #13511

    Land of 10,000 Lakes, many ponds,
    and one stubborn Neptune.
    Checked the compression after the 20 minute run,
    and it was up from 60 on both cylinders, to
    68 and 70, but I’m guessing all that extra oil had
    something to do with that!
    Put the exhaust and prop back on and threw it
    back in the test barrel…….. it did start, but the
    longest I could keep it running was about one minute.
    It kept back firing thru the carb. Adjusting the high speed
    did not seem to help. When it died, I’d have to choke it
    to restart. Not sure if I have a carb or fuel flow problem
    now, or it’s all from the crank bushing sucking air.
    In the previous 20 minute run, it didn’t backfire once!

    Prepare to be boarded!

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