New Engine Won't Start

Too much initial timing will out a huge draw on the starter. Make sure it's timed right, maybe even dial the initial back and see if it spins more freely and feed timing into it until it starts.

You really don't want to spin an engine too much that needs a camshaft broken in.

The voltage at the coil is wacky. What type of ignition are you running. If it's an MP set up, it's should have 6-8 volts in run and ~12 volts cranking as the ballast is bypassed. The draw from the starter could be taxing the entire system.

Good suggestion on the mini starter. I run junkyard specials all the time, never had one fail yet. A little powerwashing clean up and they are good to go.