Yamaha MA190, Service Manual

Page: 35 / 66

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Ignition coil
TIP
Check high tension line insulator for cracked,
replace if necessary.
Assembly:
1. Disassemble engine housing, fuel tank
and recoil starter in order.
2. Measure the clearance between the igni-
tion coil and flywheel with the feeler.
3. Adjust: Gap between the ignition coil and
flywheel.
4. Adjust method: Loosen the bolt, move
ignition coil radial along with flywheel to
adjust gap and screw down the bolt.
Check the ignition coil
(Primary side)
Measure the resistance of the primary coil by
attaching one ohmmeter lead to the ignition
coil’s primary terminal while touching the other
tester lead to the iron core.
Primary side resistance value:
1.0–1.5
Ω
(Secondary side)
Measure the resistance of the secondary side
of the coil with the spark plug cap removed,
touching one test lead to the high tension cord
while touching the other tester lead to the
coil’s iron core.
Secondary side resistance value:
5–7 k
Ω
4-3 Engine
Ignition coil
Bolt
Flywheel
Ignition gap
0.4–0.6 mm
CLEARANCE
0.4±0.2 (mm)