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. Check for runout on the commutator. If it exceeds service limits, replace the armature.






3. Check the depth of segment mold. If it exceeds service limits, replace the armature.






4. 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. If the steel sheet moves towards the core or vibrates, replace the armature.






5. 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 continuity, replace the armature.






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

3. OVERRUNNING CLUTCH
Inspect the pinion, and if there is any wear or damage, replace the overrunning clutch. Also, check that the pinion rotates counterclockwise smoothly and does not rotate clockwise. If there is any fault, replace the overrunning clutch.

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

4. BRUSH AND BRUSH HOLDER
1. Visually check the brush. If there is any abnormal wear or cracks, replace the brush.
2. Measure the length of the brush. If it exceeds service limits, replace the brush.






3. Check that the brush moves smoothly in the brush holder.
4. 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 terminal M and B.






6. SWITCH ASSEMBLY OPERATION
1. Using a lead wire, connect the terminal S 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 terminal M. Then using a lead wire, connect the positive terminal of battery and terminal M, 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. 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
AT model Max. 11 V/90 A
MT model Max. 11 V/95 A

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

2. 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
AT model 7.7 V/16.7 N.m (1.7 kgf.m, 12.3 ft.lb)
MT model 7.5 V/8.84 N.m (0.9 kgf.m, 6.5 ft.lb)

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

3. 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
AT model 3.5 V/960 A or less
MT model 4 V/680 A or less

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

8. OTHER INSPECTIONS
Check that the starter does not have deformation, cracks and any other damage.