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Model Year and Casting dates

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  • Model Year and Casting dates

    I would like to get some opinions on casting date and actual year utilized.

    If a set of motor cases is dated say, G-1 for 41 (along with vin#) would most of the other components - jugs, rocker boxes, etc, be expected to have a date code of A-0 or A-1? (A, being any month)

    I have heard that a lot of guys will use the prior year date coded parts.
    It seems like if a rocker box, for example, is dated A-1 then it more than likely went on a cycle built that year 41. Not the next


  • #2
    Most people acknowledge that date codes followed a calendar year. Production followed a model year, with the new models coming out in the fall of the previous year. So very often a part made in the end of one year, say '40, was installed on a bike that was the '41 model year machine. Some of it depends on how high an engine number is. Production basically ended late summer and nothing was built during the transition period when the assembly line was changed over. However sub-contractors were still casting parts! It isn't hard to see how previous year castings end up on the next years bike. But toward the end of that production run, the higher number machines likely had numbers from the same year they were assembled. Some exceptions would be cast iron pieces which were allowed to age before machining. Also, any replacement part would carry a later date. So attempting to have all the same year codes is not a very likely scenario in the way the manufacturing went. A few low mileage original bikes give the best examples but they also occasionally have some sort of anomaly!
    Robbie Knight Amca #2736


    • #3
      My 1945 Knuck number 177 was built in 1944. So all 1944 date codes.
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