It could be slop in the mechanism causing, as you said, the starter motor to energize before engaging the flywheel.

Another thing to check is the fly wheel. These engines always stop at one of 3 places. You might have worn teeth in those 3 places on the flywheel. If so the ring can be rotated.



"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.