Well.... on my engine, if you take off the cowl and ( looking from the propeller end in ...)vlook on the right hand side of the engine, nearest to you on the top ish... there should be two numbers.... mine was 260 141894...
from what Ive been told, the 260 is the cc, the first 3 numbers are the model and the last 3 the date....
Confirm the series number and engine number are stamped into the cylinder block - on later model this information is also on the transom mounting bracket.
the first number (260) is the Series identification number which is sometime but not always is based on the engine cc - the larger number is the production number of the motor.
To identify the age and h.p. both numbers are needed.