3 --- Starter motor rotates but engine does not turn over.
Starter motor clutch defective. Suspect jammed or worn engagement rollers, plungers and springs (early 100 models) or locking sprags (all models). Note particularly that clutch may be rendered inoperable by build-up of oily sludge, in which case stripping and flushing out is required. Modified components may be available to effect a more permanent solution.
Damaged starter motor drive train. Inspect and renew components where necessary. Failure in this area is unlikely.
© April 2014