Yamaha MX250 - Engine Care and System Checks

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PERIODIC CHECKS AND ADJUSTMENTS
PERIODIC MAINTENANCE
PERIODIC MAINTENANCE
SPARK PLUG
1.
Remove:
• Spark plug cap
• Spark plug
2.
Check:
• Spark plug type
Not correct  Replace.
• 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.
TIP
Before installing the spark plug, clean the gasket surface
and plug surface.
Check and adjust the areas around the cylinder head
after the engine has cooled down completely.
WARNING
Before removing the spark plug, use compressed air
to clean the cylinder head cover to prevent dirt from
falling into the engine.
NOTICE
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a
Spark plug type:
BPR4ES (NGK)
Feeler gauge set:
YU-26900-9
Thickness gauge:
90890-03180
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)