Reply To: Help with identifying an old outboard

[Randy in Tampa]

Bill the later speeditwin moved the spark plugs to the outside of the cylinder and the tank changed , The tank is reminiscent of the 6039 model speeditwin that started in 1939 there was a big transition between 31 and 39, I’m sure there’s another club member that knows more about the speeditwins than I do but I would lay odds that it’s a mid 30s speeditwin

Rotary valve Johnson’s Rule!