Spark Plug Inspection - Yamaha MX175 Owner's Manual

Periodic maintenance
2
1
2
1
28

Spark plug inspection

The spark plug is important engine components, which
should be checked periodically.
1. Remove the spark plug cap and the spark plug.
1. Spark plug cap
1
2. Spark plug
A MX175/MX200
B MX250/MX300/MX360/MX400
2.
Check for discoloration and remove the carbon.
The porcelain insulator around the center elec-
trode of spark plug should be a slightly colored
light gray.
3. Check the spark plug type and gap.
1. Spark plug gap
Standard spark plug:
BPR4ES (NGK)
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
TIP
The spark plug gap should be measured with a wire
thickness gauge and, if necessary, adjusted to specifi-
cation.
4.
Install the spark plug and then tighten it.
Spark plug tightening torque:
20 N·m (2.0 kgf·m, 15 lb·ft)
TIP
If a torque wrench is not available when installing a
spark plug, a good estimate of the correct torque is
1/4–1/2 turn past finger tight. However, the spark plug