• Motor is 9.9 Johnson
• Spark plugs are Champion QL77JC4 or NGK BPR7HS. Gap: 0.030“

J10RCOM

Johnson Model: J10RC0M (or J10RCOM)

Year Determination
The model J10RC0M / J10RCOM does not follow the cleanest form of the standard INTRODUCES year code, which makes an exact year slightly less straightforward.

However, based on very similar models in the Johnson parts catalogs (especially J10RC series):

Most closely matching models (J10RCUE, J10RCCD, etc.) fall in the 1987–1988 range.
The “RC” portion indicates a Rope start / Commercial / CD ignition style 9.9–10 HP motor.
The trailing “0M” or “OM” is most likely a production run / suffix letter rather than the year code.

Most probable year: 1987 or 1988