The problem is probably not in the solenoid. Since the initial solenoid "pull-in" winding that engages the starter drive gear before the armature starts turning uses the starter armature to provide its ground, the most likely cause of an intermittent "no crank" situation is either worn starter brushes or a dead spot on one of the commutator bars on the armature. Either way, you'll need to disassemble and rebuild the starter, (NOT the solenoid) or just replace the entire assembly, solenoid and starter together. I can find only one person in my neighborhood who knows how to rebuild a starter properly- - - - -and I do that by looking in a mirror! Others, including my son and grandson who have both worked as professional "mechanics", are parts changers, not journeyman mechanics!
Jerry
