Replace Brushes; Inspect Armature Commutator; Inspect Brushes - Briggs & Stratton Twin Cylinder L-Head Repair Manual

Inspect Armature Commutator

The armature commutator may be cleaned with fine
sandpaper. DO NOT use emery cloth. Commutator
may be machined to no less than 1.230" (31.24 mm),
Fig. 26.
Slots between commutator bars should be cleaned
with a hack saw blade after cleaning or machining,
Fig. 26. The slots can also be cleaned using an aerosol
carburetor cleaner or compressed air.
The armature should be checked for shorts with a
growler.

Inspect Brushes

The brushes should be checked for proper seating,
weak brush springs, dirt, oil or corrosion. Brush spring
pressure should be strong enough to ensure good
brush contact with armature. Check to be sure brushes
are not sticking in their holders.
Minimum brush dimension is 1/4" (6 mm), Fig. 27.

Replace Brushes

Three different style brush end caps are used. Refer to Fig. 28, Fig. 29 and Fig. 30 for correct location of brushes and
brush leads. Note order of assembly for insulators, washers and screws or nuts.
NOTE ROUTING OF WIRES
NEGATIVE
POSITIVE
BRUSHES
BRUSHES
Fig. 28 – Flat Coil Spring
10
6
1/4" (6 mm)
OR LESS REPLACE
NOTE ROUTING OF WIRES
POSITIVE
BRUSHES
NEGATIVE
BRUSHES
Fig. 29 – Compression Spring
PIECE OF BROKEN
HACKSAW BLADE
Fig. 26 – Cleaning Commutator
NORMAL
LENGTH, NEW
Fig. 27 – Checking Brushes
NOTE ROUTING OF WIRES
POSITIVE
BRUSHES
Fig. 30 – Compression Spring
NEGATIVE
BRUSHES