Yanmar 3TNV Series Service Manual page 164

9. Starting Motor
(2) Field coil
(a) Field coil continuity test
Check continuity between field coil terminals. Good if
continuity exists.
If no continuity (coil disconnection), replace the field
coil.
(b) Field coil insulation test
Check continuity between field coil terminal and yoke.
Good if no continuity exists.
If continuity exists (coil short circuit), replace the
armature.
(3) Brush
Measure the length of the brush. Replace with a
good one if the length is less than the limit.
mm
Standard Limit
15 9
149