Yamaha MX250 - Checking the Spark Plug Cap Resistance

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ELECTRICAL
ELECTRICAL COMPONENTS
2.
Check:
• Spark plug condition
Wear/damage  Replace.
(Refer to “SPARK PLUG” on page 2-3)
3.
Check:
• Ignition spark gap
Out of specification  Perform the ignition system
troubleshooting, starting with step 8.
(Refer to “ENGINE DOES NOT START” on page
6-1)
TIP
If the ignition spark gap is within specification, the ignition
system circuit is operating normally.
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a. Disconnect the spark plug cap “1” from the spark
plug.
b. Connect the ignition checker “2” as shown.
c. Connect the ignition checker lead to spark plug “3”
as shown.
d. Set the engine switch to “ON”.
e. Pull the recoil starter handle.
f. Measure the ignition spark gap “a”.
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CHECKING THE SPARK PLUG CAP RESISTANCE
1.
Remove:
• Spark plug cap
2.
Check:
• Spark plug cap resistance
Out of specification  Replace the spark plug cap.
Minimum ignition spark gap:
6.0 mm (0.24 in)
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Oppama pet–4000 spark checker:
YM-34487
Ignition checker:
90890-06754
Spark plug cap resistance:
3.75–6.25 k