gjberche,

I could be wrong, but I don't think any engine made is timed to fire ATDC...retarded. Opening the points BEFORE the piston reached top dead center is sort of like leading a duck with your shot gun sights. It takes time for all the ignition stuff to happen as well as the fuel/air mixture to ignite and burn. The firing has to "lead" the pistons arrival at TDC to maximize the process.

I think there are two schools of thought. Use marks or BB's, or time it until it runs the best with no detonation or abnormal heating.

The marks will get you in the ball park, and they should be accurate, but it isn't against the law to fiddle until you are happy with it.

When you and your dad timed it, did you remember to disconnect the vacuum line at the carburetor and plug the port into the carb...maybe this is why it won't start now.

How did you determine it was 8&deg ATDC...did you use a advance timing light?

Stuart