Starter Motor Inspection

Starter

INSPECTION

1. ARMATURE
1. Check the commutator for signs of seizure or stepped wear caused by roughness of the surface. If there is light wear, use sandpaper to repair.
2. Runout test Check for runout on the commutator. If excessive, replace it.






3. Depth of segment mold
Check the depth of the segment mold.






4. Armature short.circuit test
Place the armature on the growler tester to check for short circuits. While slowly turning the armature, support the steel sheet for the armature core. If the circuit of the armature is shorted, the steel sheet will vibrate, causing it to move towards the core. When the steel sheet has moved or vibrated, replace or repair the armature with the shorted circuit.






5. Armature ground test
Use a circuit tester to touch the probe of one side to the commutator segment, and the other probe to the shaft. If there is no continuity, it is normal. If there is continuity, the armature is grounded. If grounded, replace the armature.






2. YOKE
Make sure that the pole is set at the predetermined position.

3. OVERRUNNING CLUTCH
Check that there is no wear or damage to the piston teeth. Replace if it is damaged. If it rotates smoothly when rotated in the correct direction (counterclockwise) and does not return to the other direction, it is normal.

CAUTION: To prevent spilling of grease, do not clean the overrunning clutch with oil.

4. BRUSH AND BRUSH HOLDER
1. Brush length
Measure the length of the brush. If it exceeds service limits, replace it.
Replace if there is abnormal wear or cracks.






2. Brush movement
Check that the brush moves smoothly in the brush holder.
3. Brush spring force
Measure the brush spring force with a spring scale.
Replace the brush holder if below the service limit.

Brush spring force:
Standard 15.9-19.5 N (1.62-1.99 kgf, 3.57-4.38 lbf) (When new)
Service limit 2.5 N (0.25 kgf, 0.56 lbf)

5. SWITCH ASSEMBLY
Using a circuit tester (set to ohm ), check that there is continuity between terminals S and M, and between terminal S and ground.
Also check to be sure there is no continuity between M terminal and B.






6. SWITCH ASSEMBLY OPERATION
1. Using a lead wire, connect the S terminal of switch assembly to positive terminal of battery, and starter body to ground terminal of battery. The pinion should be forced endwise on shaft.

NOTE: With the pinion forced endwise on shaft, starter motor can sometimes rotate because current flows, through pull.in coil, to motor. This is not a problem.

2. Disconnect the connector from M terminal. Then using a lead wire, connect the positive terminal of battery and M terminal and ground terminal to starter body.
In this test set up, the pinion should return to its original position even when it is pulled out with a screwdriver.






7. PERFORMANCE TEST
The starter should be submitted to performance tests whenever it has been overhauled, to assure its satisfactory performance when installed on the engine.
Three performance tests, no.load test, load test, and lock test, are presented here; however, if the load test and lock test cannot be performed, carry out at least the no.load test. For these performance tests, use the circuit shown in figure.






1. No.load test
With switch on, adjust the variable resistance until the voltage is 11 V, read the value of ammeter to measure starter speed. Compare these values with the standard.

No.load test (standard):

Voltage/Current
MT model Max. 11 V/95 A
AT model Max. 11 V/90 A

Rotating speed
MT model 2,500 rpm or more
AT model 2,000 rpm or more

2. Load test
Apply the specified braking torque to starter. The condition is normal if the current draw and starter speed are within standard.

Load test (standard):

Voltage/Load
MT model 7.5 V/8.84 N.m (0.9 kgf.m, 6.5 ft.lb)
AT model 7.7 V/16.7 N.m (1.7 kgf.m, 12.3 ft.lb)

Current/Speed:
MT model 300 A/870 rpm or more
AT model 400 A/710 rpm or more

3. Lock test
With the starter stalled, or not rotating, measure the torque developed and current draw when the voltage is adjusted to standard voltage.

Lock test (standard):

Voltage/Current
MT model 4 V/680 A or less
AT model 3.5 V/960 A or less

Torque
MT model 17 N.m (1.7 kgf.m, 12.5 ft.lb) or more
AT model 31 N.m (3.2 kgf.m, 22.9 ft.lb) or more