Yanmar 3TNV Series Service Manual page 166

9. Starting Motor
(b) Series coil continuity test
Check continuity between the S and M terminals.
Good if continuity exists.
If no continuity (coil disconnection), replace the
magnetic switch.
(c) Contact continuity test
Depress the magnetic switch with the plunger at the
bottom. Check continuity between the B and M
terminals with a multimeter. Good if continuity exists.
If no continuity (coil continuity defect), replace the
magnetic switch.
(6) Pinion clutch
(a) Pinion inspection
Manually rotate the pinion. Inspect if it is rotated
smoothly in the driving direction, and is locked in the
opposite direction. Replace the pinion clutch if
abnormal.
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