Yanmar 4LHA-HTP Operation Manual page 642

Chapter 9 Electrical System
3. Starter Motor
10 Troubleshooting
(1) Pinion fails to advance when the starting switch is closed
Problem
Wiring
Starting switch
Starter motor
Magnetic switch
Problem
Starting motor
(3) Motor rotates at full power before pinion engages ring gear
Problem
Starter motor
(4) Pinion engages ring gear, but starter motor fails to rotate
Problem
Wiring
Starter motor
Magnetic switch
Problem
Starting switch
Magnetic switch
Open or loose battery or switch terminal
Threaded part connected to pinion section of armature shaft
is damaged, and the pinion does not move
Threaded part connected to pinion section of armature shaft
is damaged, and the pinion does not move
Plunger of magnetic switch malfunctioning or coil
shorted
Cause
Overrunning clutch faulty
Cause
Torsion spring permanently strained
I
Wires connecting battery and magnetic switch open
or wire connecting ground, magnetic switch and motor
terminals loose
Pinion and ring gear engagement faulty
Motor mounting faulty
Brush worn or contacting brush spring faulty
Commutator dirty
Armature, field coil faulty
Field coil and brush connection loose
Contactor contact faulty
Contactor contacts pitted
Switch faulty
Switch faulty
Cause
Cause
Cause
9-16
, 4LHA Series
Corrective action
Repair or retighten
Repair contacts,
or replace switch
Replace
Repair or replace
Corrective action
Replace
Corrective action
Replace
Corrective action
Repair, retighten,
or replace wire
Replace
Remount
Replace
Repair
Repair or replace
Retighten
Replace
Replace
Corrective action
Replace
Replace