Briggs & Stratton Twin Cylinder L-Head Repair Manual page 12

BRIGGS & STRATTON NUMERICAL IDENTIFICATION SYSTEM
All Briggs & Stratton engines have a unique numerical identification system. Each engine is identified by a Model, Type
and Code number. Example:
This chart explains the numerical model designation system. It is possible to determine most of the important
mechanical features of the engine by merely knowing the model number. Here is how it works.
FIRST DIGIT
AFTER DISPLACEMENT
CUBIC INCH BASIC
DISPLACEMENT DESIGN SERIES
The type number identifies certain unique features such as the crankshaft or governor spring used on an engine.
The code number identifies the assembly date of the engine. In some instances it is necessary to know the code number
as well as the model and type number when performing adjustments, repairs or ordering replacement parts for an
engine. Here is how it works.
Example: 99052115
A. The first two digits, 99, indicate the calendar year, 1999.
B. The second two digits, 05, indicate the calendar month, May.
C. The third two digits, 21, indicate the calendar month day.
D. The last two digits, 15, indicate the assembly line or manufacturing plant.
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Model Type Code
422777 1125 01 99052115
SECOND DIGIT
AFTER DISPLACEMENT
CRANKSHAFT,
CARBURETOR,
GOVERNOR
THIRD DIGIT
AFTER DISPLACEMENT AFTER DISPLACEMENT
PTO BEARING,
REDUCTION GEAR,
AUXILIARY DRIVE,
LUBRICATION
FOURTH DIGIT
TYPE OF STARTER
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