203711 is the casting number on crankshafts from 1956 Evinrude/Johnson 15 HP motors. That number is shown in the attached photo of a crankshaft I removed from either a 1956 Evinrude or Johnson 15 HP. So that casting would have been machined to be crankshaft 277594.
Brought back this old thread as that info may be helpful to someone working on one of these motors.
Yeah, you must be real careful with those “casting numbers” on parts. Not necessarily the actual part number…
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