To find an exact anwser to your question is important to know the brand of your outboard motor, horse power (h.p.) and ehether is a two stroke or four stroke.
Look for a little plate on the motor' mounting bracket or also at the crankcase stamped (earlier outboard models)
here you will find an outboard model year guide:
Johnson Outboard Serial Number Lookup
Johnson Motor Serial Number Location
We just bought a 1970 boat with an Evinrude 25 hp motor. The serial or model number is 25102S or 251025, there is another number: E06126. We don't know if the motor is the first one for that boat or many of several, but one site I looked at indicated the motor to be a 1971.
Evinrude Johnson OMC model guide
Includes Evinrude, Johnson, Gale, OMC outboard derivatives.
OMC Johnson/Evinrude Model Identification 1980-2004
Johnson Serial Number Search
STYLE J = Johnson E = Evinrude
HORSEPOWER
SHAFT LENGTH (blank)= 15 in. L = 20 in. Y = 22.5 in. X = 25 in. Z = 30 in.
MODEL RUN or SUFFIX(The Suffix codes and any codes before the Style entry aren't important to consumer)
DESIGN FEATURE 3 = 3-Cylinder (25 or 35 HP) 1999 up 4 = Four-Stroke Motor AE = Electric Start (Alaska Model) AR = Rope Start (Alaska Model) BA = AC Lighting (Rope Start) BE = Belgium Derated (Electric Start) BF = Belgium Derated (Rope Start) BG = Belgium Derated (Rope Start) BI = Belgium Derated (Rope Start) BR = Euro Rope Start C = Counter Rotation CE = Canada Derated (Electric Start) CR = Canada Derated (Rope Start) D = Remote Electric DE = Derated (Electric Start) DR = Derated (Rope Start) DT = Derated (Electric Start/Trim & Tilt)) E = Electric Start (Remote Steering) ER = Electric Start (Sport Styling) ES = Electric Start (Special) F = FICHT™ Fuel Injection (2000 up) FA = 4-Stroke (Rope Start - AC Lighting) FE = 4-Stroke (Electric Start - Tiller) FP = Commercial (w/Programmed Tilt) FR = 4-Stroke (Rope Start) FRE = 4-Stroke (Electric Start/Remote) FS = FICHT™ (Trim & Tilt) FT = FICHT™ (Trim & Tilt - Special Styling)) G = Special Styling H = Less Integral Fuel Tank I = FICHT™ Fuel Injection (98 & 99) IE = Italy (Electric Start) IK = Italy (Electric Start) J = Jet Drive Outboard K = 3-Cylinder (25 or 35 HP) thru 1998 KC = Kerosene (Rope Start) KG = Kerosene/Gasoline KS = Kerosene (Rope Start) M = Manual Tilt Electric Start (thru 1998) M = Manual Tilt (V4) 1999 up N = Counter Rotation P = Power Trim/Power Steering Q = 3-Cylinder (25 or 35 HP) thru 1998 R = Rope Start Tiller RA = Australia Rope Start RC = Rope Start (Commercial/CD Ignition) RD = Rope Start (Deluxe) RE = Remote Electric (thru 1998) RP = Commercial w/Programmed Tilt RS = Rope Start (Commercial Model) RW = Commercial w/Interlock S = Sail/Special Styling (Evinrude White) SC = Special Styling Counter Rotation SE = Sail Electric Start Non-Tilt SI = Italy Special Derated SL = 60° V, Trim & Tilt SP = Special Styling SR = Sail Rope Start Non-Tilt ST = Special Styling Trim & Tilt T = Electric Start Trim & Tilt TE = Tiller Electric TR = Trim & Tilt (Sport Styling) TT = Trim & Tilt (Tiller Backtroller) U = Manual Tilt V = Special Gearcase W = Rope Start (Commercial) WM = Commercial Rope Start Manual Tilt WMP = Same as WM w/Chrome Water Pump WT = Commercial Electric Start (Trim & Tilt) WTP = Same as WT w/Chrome Water Pump
YEAR BUILT(Match letter to number)
EXAMPLES: CS = 1980EI = 1991SN = 2002 Example above: E70PLEEA is an Evinrude 70HP Power Trim 20' shaft 1999 'A' suffix
Mercury and Mariner US build 40HP and over
For mercury outboard motors from the early 60' to 1999
