Does it ever end?

Guess you didn’t see post 18. If you have a needle hang open on a carb and an electric fuel pump it will hydraulic. Even if ever so slightly it will kick back the starter and try to break it. Hell it’s possible with a mechanical pump also if you had to crank it a while. What was the starting process like this time?
Mechanical pump with regulator set at 5.5psi
It didn't crank long started after initial kickback