Spark Plug Inspection - Yamaha G21A Owner's/Operator's Manual

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Y-516
Y-37

Spark Plug Inspection

You should periodically remove and
inspect the spark plug. Dirty or worn
spark plugs can cause poor perfor-
mance.
å Spark plug
∫ Spark plug cap
1. Check for discoloration and heavy
carbon deposits.
electrode color will be tan. If it is
not, replace it.
2. Check the spark plug type, and
check the spark plug gap with a
feeler gauge.
Standard spark plug:
BPR2ES or BPR4ES
Spark plug gap:
0.028 ˜ 0.031 in (0.7 ˜ 0.8 mm)
å Gap
3. Clean the gasket and plug sur-
faces and install the spark plug fin-
ger tight before tightening to the
following torque:
Spark plug torque:
14.5 ft . lb
(20 Nm, 2.0 m . kg)
WARNING
When removing or installing the
spark plug, be careful not to dam-
age the insulator. A damaged insu-
lator could allow external sparks,
which could lead to explosion or
fire.
The normal
UTILITY