Periodic Maintenance; Spark Plug - Yamaha MX250 Service Manual

PERIODIC MAINTENANCE

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PERIODIC MAINTENANCE

SPARK PLUG

WARNING
Check and adjust the areas around the cylinder head
after the engine has cooled down completely.
1.
Remove:
• Spark plug cap
• Spark plug
NOTICE
Before removing the spark plug, use compressed air
to clean the cylinder head cover to prevent dirt from
falling into the engine.
2.
Check:
• Spark plug type
Not correct  Replace.
Spark plug type:
1
• Electrode "1"
Wear/damage  Replace.
• Insulator color "2"
Not normal  Replace.
3.
Measure:
• Spark plug gap "a"
Use a wire gauge or feeler gauge set.
Out of specification  Regap.
If necessary, clean the spark plug with a spark plug
cleaner.
Feeler gauge set:
Thickness gauge:
Spark plug gap:
TIP
Before installing the spark plug, clean the gasket surface
and plug surface.
2-3
BPR4ES (NGK)
YU-26900-9
90890-03180
0.7–0.8 mm (0.028–0.031 in)
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