Re: Deciphering old model numbers
In the 1950s, Johnson would begin a model series with 10 and work their way up each year/model change. For example, the RD-10 was the 1951 model 25hp, the FD-10 was the 1956 15hp, etc. Similar models in the series went from 25 to 30 to 35 to 40hp. Similar models within a model family might get a different second letter (.ie RJE-18, RX-24). A few models were made for more than one year and the model number stayed the same. Models prior to WWII were a bit more difficult to decipher as some had the second two digits as the year (PO-38 was a 1938, LT-39 was a 1939, etc.) but earlier models went by increments of 5 each year. Bottom line is that it is best to look them up in the book... NAPA used to print the model number lists in their marine parts catalogs. I've seen them elsewhere, too...
- Scott
