Briggs & Stratton 203985GS Operator's Manual page 20

Service Air Cleaner
Your engine will not run properly and may be damaged if
you run it with a dirty air cleaner.
Clean or replace the foam pre-filter every 25 hours of
operation or sooner under dusty or dirty conditions. Clean or
replace the paper air filter every 100 hours of operation or
yearly, whichever comes first. Clean or replace more often if
operating under dusty or dirty conditions.
To service the air cleaner, follow these steps:
1. Loosen knobs and swing air cleaner cover (A) to the
side.
B
E
2. Remove cover and air cleaner assembly from base (B).
3. Carefully remove cartridge retainer (C) and pre-cleaner
(D) from paper filter (E).
4. Wipe clean inside of base and cover thoroughly.
5. Clean or replace the foam pre-cleaner. Wash pre-
cleaner in a solution of household detergent and warm
water, then rinse thoroughly. Squeeze dry in a clean
cloth. DO NOT twist.
6. Saturate foam pre-cleaner in clean engine oil and
squeeze in a clean, absorbent cloth to remove all
excess oil. DO NOT twist.
IMPORTANT: The engine will smoke during initial start-up if
too much oil is left in the pre-cleaner.
7. Clean paper filter by tapping it gently on a solid surface.
If the paper filter is too dirty, replace it with a new one.
Dispose of the old filter properly.
8. Reinstall pre-cleaner on retainer.
9. Install pre-cleaner in cover with mesh side toward
paper filter. Install paper filter in cover or on base.
10. Assemble air cleaner assembly and cover onto base
and tighten knobs.
20
Service Spark Plug
Change the spark plug every 100 hours of operation or once
each year, whichever comes first. This will help your engine
to start easier and run better.
C
D
A
1. Clean area around spark plug.
2. Remove and inspect spark plug.
3. Check electrode gap with wire feeler gauge and reset
spark plug gap to recommended gap if necessary (see
Specifications).
4. Replace spark plug if electrodes are pitted, burned or
porcelain is cracked. Use the recommended
replacement spark plug. See Specifications.
5. Install spark plug and tighten firmly.
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