Having taken a closer look, and compared it with the other two 1s in the string of numbers, I agree with you Joe - I can't tell either. Seems like your advice was better than mine - alwayscurious needs to trace the wires from the module, in case there is one leading into the housing under the flywheel. At least he'll then know whether his engine is 1981 or 1987.
Part of my reason for thinking it was 87 is the radial pull starter - I thought they were all vertical pull in the early 80s.
