<VV> Frustrating Weekend/ Starter

[Smitty Smith]

Smitty Says:  A starter with worn bearings or one with a bent shaft will spin fine without a load but struggle when trying to turn an engine.  The armature will clear the static poles OK when no load but will be close enough to the static poles that when under load  the magnatism will snatch the armature up against the poles.  The effective magnatism at contact creating a mechanical drag can stall the motor out.  Not saying this is your problem but it needs considering.