EBS01064 CHECKING THE STARTER MOTOR 1. Check: commutator Dirt Clean with 600-grit sandpaper. 2. Measure: commutator diameter a Out of specification Replace the starter motor. a 3. Measure: mica undercut a Out of specification Scrape the mica to the proper measurement with a hacksaw blade that has been grounded to fit the commutator. NOTE: _ The mica of the commutator must be undercut to ensure proper operation of the commutator. 4. Measure: armature assembly resistances (commutator and insulation) Out of specification Replace the starter motor. 9 - 24 STARTER MOTOR ELEC – + ELEC – + Commutator wear limit 27 mm (1.06 in) Mica undercut 0.70 mm (0.03 in)