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  1. #1
    Cadet
    Join Date
    Jan 2004
    Location
    IL
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    29

    Default 1966 JW21 3hp Sync Help

    I have seen one other post on this with no answer to the subject. Manual states that there will be an index mark on the cam for syncing. There is no mark on the cam on this motor. Suggestion on how to make sure that this one is set correctly? Right now it runs at high but dies at idle - I am guessing I am running on one cylinder which I will check first. Carb is clean. Coils are good and had good 1/4 jump at test - no followup on if it still does as it started raining. Please let me know on the cam and cam follower. Thnx.

  2. #2
    Supreme Mariner
    Join Date
    Jul 2006
    Location
    Florida Gulf Coast
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    17,851

    Default Re: 1966 JW21 3hp Sync Help

    I can't guarantee this applies to that particular year, but on many there is a shallow indent on the bottom of the tank support, above the sliding throttle control arm, toward the "slow" end. If it is there, that is the index mark where the carb barely starts to open.

  3. #3
    Captain nwcove's Avatar
    Join Date
    May 2011
    Location
    nova scotia, canada
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    3,715

    Default Re: 1966 JW21 3hp Sync Help

    just brought the same motor back to life. if you did a complete carb overhaul....pay close attention to the parts you replace. dont want to highjack, so i will post the problem i had in my thread.
    give a man a fish, and he will eat all day. teach a man how to fish, and he will sit in a boat all day and drink beer.

  4. #4
    Cadet
    Join Date
    Jan 2004
    Location
    IL
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    29

    Default Re: 1966 JW21 3hp Sync Help

    well, i do not notice anything that f_r mentions. i did run it in the barrel again and hooked timing light on it running and it flashes. pulled one plug at a time and it stuttered on each. and did spark in the dark - still good. so i fired it up again and sprayed carb cleaner around packing nut - ok. then on head and when i got to the lower rt side by the exhaust side it bogged and then picked up. damn head gasket.

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