Wiring Diagram Of A Starting Motor; Performance - Yanmar 2TNV70 Service Manual

8. The specifications of a starting motor and the characteristics

8.2.2 Wiring diagram of a starting motor

1) When a starting switch is turned on, a magnet
switch is charged, and a moving core is absorbed,
and a pinion clutch is moved forward through a
lever, and the pinion engages with a ring gear.
2) When the pinion engages the ring gear, because
a main contact point is closed and the main
electric current flows and a pull coil is
short-circuited by the main contact point and it
stops being charged with electricity, the pinion is
kept at the position by a holding coil during the
start,
3) When the starting switch is turned off, the main
contact point becomes open, and the pinion
clutch is returned to the stop position by a return
spring.

8.3 Performance

The specified characteristics of a starting motor (at 20 deg. C)
1) No load: Less than electric current 90A, more than rotation speed 3000min
2) Load: More than rotation speed 1130 min-1, torque 6.86 N m (0.70kg f m) at voltage 8.7V and
electric current 230A.
3) Restraint: Less than electric current 325A, torque 8.2 N m (0.84 kgf m) at voltage 2.5V.
4) Operation voltage: In the position of a ring gear, less than 8V
Since the characteristics of a starting motor can be confirmed easily in the no-load test comparatively,
perform the test by the next point.
No-load test
Fix the starting motor on a test bench and connect wiring. When the switch is closed, a current flows
in the starting motor, which is rotated at no-load. Measure the current, voltage and number of
revolutions then and check if they satisfy the specified characteristics.
99
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at voltage 11.5V.