12
Spark Plug Service
NOTICE
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 in (21 mm)
spark plug wrench.
3. Inspect the spark plug.
Replace it if the electrodes
are worn or if the insulator is
cracked, chipped, or fouled.
4. Measure the spark plug
electrode gap with a suitable
gauge. The gap should be
0.028 ~ 0.031 in (0.7 ~ 0.8 mm).
Correct the gap, if necessary,
by carefully bending the side
electrode.
5. Install the spark plug carefully,
by hand, to avoid
cross-threading.
6. After the spark plug seats,
tighten with a 13/16 in (21 mm)
spark plug wrench to compress the washer.
If reinstalling the old spark plug, tighten 1/8 to 1/4 turn after the
spark plug seats.
If installing a new spark plug, tighten 1/2 turn after the spark plug
seats to compress the sealing washer.
NOTICE
A loose spark plug can overheat and damage the engine.
Overtightening the spark plug can damage the threads in the
cylinder head.
7. Install the spark plug cap on the spark plug.
Spark Arrester Service (optional equipment)
Your lawn mower engine is not factory-equipped with a spark arrester.
In some areas, it is illegal to operate an engine without a spark
arrester. Check local laws and regulations. An optional USDA
approved spark arrester is available from an authorized Honda
servicing dealer. See page 18 for part numbers.
The spark arrester must be serviced every 100 hours to keep it
functioning as designed.
1. Allow the engine to cool and disconnect the spark plug cap.
2. Remove the three flange bolts and the heat shield. Remove the set
screw and the spark arrester from the muffler.
3. Inspect the spark arrester; replace it if the screen is damaged.
4. Check for carbon deposits on the spark arrester and the exhaust
port. Brush carbon deposits away. Be careful to avoid damaging
the spark arrester screen.
5. Installation is the reverse of removal. Tighten all hardware
securely.
6. Reconnect the spark plug cap.
Blade Control Operation Check
Start the engine outdoors. Release the blade control lever; the engine
should stop quickly. If the engine does not stop quickly, take the
mower to an authorized Honda servicing dealer for repair.
RECOMMENDED SPARK PLUG NGK BPR5ES
SPARK PLUG
SPARK
PLUG
CAP
SPARK PLUG
WRENCH
0.028 ~ 0.031 in
(0.7 ~ 0.8 mm)
SEALING
WASHER
SET SCREW
SPARK ARRESTER
FLANGE BOLT (3) HEAT SHIELD