With my experience as a small engine mechanic the magnet to the ignition system is the best way to rotate engine as long as the spark plug is removed from the head and the clutch arm is pushed in to disengage the clutch. The motor should spin. The ignitions magneto gap might need to be adjusted to allow the engine to rotate. Sometimes parts shift during shipping.

I had to put motor together I no machinic so I did my best to figure it out with no instructions so if something is not write and blows up you folks will be giving me a new motor

It probably has metal shavings in all the bearings or a broken ring jammed in between the piston and cylinder I know it happened to me!