Periodic Maintenance - Yamaha EH63 Service Manual

PERIODIC MAINTENANCE

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PERIODIC MAINTENANCE
SPARK PLUGS
The following procedure applies to all of the spark plugs.
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 thickness gauge.
Out of specification  Adjust.
If necessary, clean the spark plug with a spark plug
cleaner.
Thickness gauge:
Feeler gauge set:
Spark plug gap:
2-3
BPR5ES (NGK) (Except for EH64A)
BPR4EY (NGK) (EH64A)
90890-03268
YU-26900-9
0.7–0.8 mm (0.028–0.031 in) (Except for
EH64A)
0.6–0.7 mm (0.024–0.028 in) (EH64A)
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