Yamaha MBK MW125 2014 Service Manual

ELECTRICAL COMPONENTS8-64c. Measure the primary coil resistance.▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲2. Check:• Secondary coil resistanceOut of specification → Replace.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Connect the pocket tester (Ω × 1k) to the ig-nition coil as shown.b. Measure the secondary coil resistance.▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲EAS30556CHECKING THE IGNITION SPARK GAP1. Check:• Ignition spark gapOut of specification → Perform the ignitionsystem troubleshooting, starting with step 5.Refer to “TROUBLESHOOTING” on page8-3.TIPIf the ignition spark gap is within specification,the ignition system circuit is operating normally.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Remove the ignition coil from the spark plug.b. Connect the ignition checker “1” as shown.c. Turn the main switch to “ON”.d. Measure the ignition spark gap “a”.e. Crank the engine by pushing the “ ” of thestart switch and gradually increase the sparkgap until a misfire occurs.▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲EAS30560CHECKING THE CRANKSHAFT POSITIONSENSOR1. Disconnect:• Crankshaft position sensor coupler(from the wire harness)2. Check:• Crankshaft position sensor resistanceOut of specification → Replace the crank-shaft position sensor.▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼a. Connect the pocket tester (Ω × 100) to thecrankshaft position sensor coupler as shown.Secondary coil resistance8.64–12.96 kΩPocket tester90890-03112Analog pocket testerYU-03112-C• Positive tester probe →red/white “1”• Negative tester probe →High tension cord “2”2121Minimum ignition spark gap6.0 mm (0.24 in)Ignition checker90890-06754Oppama pet–4000 spark checkerYM-344872. Ignition coilCrankshaft position sensor resis-tance228–342 Ω (W/L-W/R)