Starting Motor Inspection: Armature

Inspect commutator for dirt or burn. Correct with sandpaper or lathe, if necessary.

Fig 1: Inspecting Commutator For Dirt Or Burn
Courtesy of SUZUKI OF AMERICA CORP.
Check commutator for uneven wear with armature (1) supported on V-blocks (2). If deflection of dial gauge (4) pointer exceeds limit, repair or replace.
NOTE: The following specification presupposes that the armature is free from bend. Bent armature must be replaced.

Commutator out of round

Standard: 0.05 mm (0.002 in.) or less

Limit: 0.4 mm (0.015 in.)

Fig 2: Checking Commutator Uneven Wear With Armature
Courtesy of SUZUKI OF AMERICA CORP.
Inspect the commutator for wear. If diameter is below limit, replace the armature.
Commutator outside diameter

Standard: 29.4 mm (1.16 in.)

Limit: 28.8 mm (1.13 in.)

Fig 3: Measuring Commutator Outside Diameter
Courtesy of SUZUKI OF AMERICA CORP.
Inspect the commutator (1) for insulator (2) depth. Correct or replace if below limit.
Commutator insulator depth "a"

Standard: 0.4 - 0.6 mm (0.015 - 0.024 in.)

Limit: 0.2 mm (0.008 in.)

Fig 4: Measuring Commutator Insulator Depth
Courtesy of SUZUKI OF AMERICA CORP.
Check the commutator and armature core. If there is continuity, the armature is grounded and must be replaced.

Fig 5: Checking Commutator And Armature Core
Courtesy of SUZUKI OF AMERICA CORP.
Check for continuity between segments. If there is no continuity at any test point, there is an open circuit and the armature must be replaced.

Fig 6: Checking Continuity Between Segments
Courtesy of SUZUKI OF AMERICA CORP.