C;
Did you prime the oil pump?? Try turning it with the plugs out after priming (if you didn't) with a 12V Batt.
An old 6V starter can be a pain. Easy to fix though. In the 50s I/we all had the same problem. I just rolled down the hill to start the 'tight/new ones' etc.
The brush springs get weak and don't hold the brush(s) especially the old ones tight against the comuntator.
It will spin good W/O plugs on 12V, you'll see.
JM.........
