Spark Plug - Honda GX120 Owner's Manual

AIR CLEANER
A dirty air cleaner will restrict air flow to the carburetor, reducing
engine performance. If you operate the engine in very dusty areas,
clean the air filter more often than specified in the MAINTENANCE
SCHEDULE.
Operating the engine without an air filter, or with a damaged air
filter, will allow dirt to enter the engine, causing rapid engine wear.
This type of damage is not covered by the Distributor's Limited
Warranty.
Inspection
1. Release the retaining clip, and remove the air cleaner cover.
2. Remove and inspect the air filter elements. If the air filter
element is dirty, clean the air filter elements as described below.
Replace damaged filter elements. Always replace the paper air
filter element at the scheduled interval (see page
3. Place the foam air filter element over the paper element, and
reinstall the assembled air filter elements. Insert the open end of
the air filter elements into the case as shown, so the closed end
is toward the air cleaner cover.
4. Hook the bottom edge of the air cleaner cover onto the case,
then secure the cover with the retaining clip.
RETAINING CLIP
PAPER FILTER ELEMENT
CLOSED END
FOAM FILTER ELEMENT
AIR CLEANER COVER
Cleaning
1. Clean the air filter elements if they are to be reused.
Paper air filter element: Tap the filter element several times on a
hard surface to remove dirt, or blow compressed air [not
exceeding 207 kPa (2.1 kgf/cm , 30 psi)] through the filter
element from the inside. Never try to brush off dirt; brushing will
force dirt into the fibers.
Foam air filter element: Clean in warm soapy water, rinse, and
allow to dry thoroughly. Or clean in non-flammable solvent and
allow to dry. Dip the filter element in clean engine oil, then
squeeze out all excess oil. The engine will smoke when started if
too much oil is left in the foam.
2. Wipe dirt from the inside of the air cleaner case and cover, using
a moist rag. Be careful to prevent dirt from entering the air duct
that leads to the carburetor.
8
5
).
AIR CLEANER CASE
OPEN END
INCORRECT
CORRECT
PLATE

SPARK PLUG

Recommended Spark Plugs:
The recommended spark plug has the correct heat range for
normal engine operating temperatures.
An incorrect spark plug can cause engine damage.
For good performance, the spark plug must be properly gapped
and free of deposits.
1. Disconnect the spark plug cap,
and remove any dirt from
around the spark plug area.
2. Remove the spark plug with a
13/16-inch spark plug wrench.
3. Inspect the spark plug.
Replace it if damaged or
badly fouled, if the sealing
washer is in poor condition,
or if the electrode is worn.
4. Measure the spark plug
electrode gap with a wire-
type feeler gauge. Correct the
gap, if necessary, by carefully
bending the side electrode.
The gap should be:
0.7 0.8 mm (0.028 0.031 in)
5. Install the spark plug carefully,
by hand, to avoid cross-
threading.
6. After the spark plug is seated, tighten with a 13/16-inch spark
plug wrench to compress the sealing washer.
7. When installing a new spark plug, tighten 1/2 turn after the spark
plug seats to compress the washer.
8. When reinstalling the original spark plug, tighten 1/8 1/4 turn
HOLE
after the spark plug seats to compress the washer.
A loose spark plug can overheat and damage the engine.
Overtightening the spark plug can damage the threads in the
cylinder head.
9. Attach the spark plug cap to the spark plug.
ENGLISH
BP4ES (NGK)
W14EP-U (DENSO)
SPARK PLUG WRENCH
SIDE ELECTRODE
0.7 0.8 mm
(0.028 0.031 in)
SEALING
WASHER