Special Tool - Hand Tester: 57001-1394
If there is a high resistance or no reading (∞) between any two segments, a winding is open and the starter motor must be replaced.
If there is any reading at all, the armature has a short and the starter motor must be replaced.

NOTE
Even if the foregoing checks show the armature to be good, it may be defective in some manner not readily detectable with the hand tester. If all other starter motor and starter motor circuit components check good, but the starter motor still does not turn over or only turns over weakly, replace the starter motor with a new one.
Commutator Cleaning and Inspection
Brush Lead InspectionLower Crankcase Assembly
Install the ball bearing [A] and the oil level inspection window
[B] until they are bottomed
Apply soap and water solution to the oil level inspection
window before installation.
Install the new circlip [C].
Apply a non-permanent locking agent to the oil passage
plug [D].
Tighten: ...
Balance Weight Installation
Check if the weight portion has any play on the blade [A]
and clip [B].
If it does, discard it.
WARNINGUnbalanced wheels can create an unsafe
riding
condition. If the balance weight has any play on
the rib of the rim, the blade and/or clip have been
stretched. Replace th ...
Ignition System
WARNINGThe ignition system produces extremely
high voltage.
Do not touch the spark plug, ignition coil or ignition
coil lead while the engine is running, or you
could receive a severe electrical shock.
NOTICE
Do not disconnect the battery cables or any other
electrical ...