John,
How did you set the timing?
You might want to check the timing again. Rotate the engine until the ball on the flywheel lines up with the pointer on the clutch housing - make sure both #1 valves are closed (open lash - rocker arms loose).
What is the firing-order of your ignition wires (clockwise rotation)?
Where are you observing "good spark"? At the spark plugs?
