Briggs & Stratton 133200 Series Operating & Maintenance Instructions page 16

SERVICE & STORAGE
STORAGE
Engines stored over 30 days need special attention.
[1] To prevent gum from forming in fuel system or on
essential carburetor parts:
a) if fuel tank contains oxygenated or reformulated
gasoline (gasoline blended with an alcohol or an
ether), run engine until it stops from lack of fuel, or b) if
fuel tank contains gasoline, either run engine until it
stops from lack of fuel, or add a gasoline additive to the
gas in the tank. (See parts list. Single – use pouches of
gas additive are available from your service dealer.) If
you use a gas additive, run the engine for several
minutes to circulate the additive through the carburetor.
Then, engine and fuel can be stored up to 24 months.
[2] While engine is still warm, change oil.
[3] Remove spark plug and pour about 1/2 oz. (15 ml) of
engine oil into cylinder. Replace spark plug and crank
slowly to distribute oil.
[4] Clean engine of surface debris, chaff or grass.
[5]
WARNING
16
Store in a clean, dry area.
Do not store in same area
as a stove, furnace, water
heater, or other appliance
that uses a pilot light or
has a device that can
create a spark.