Starting issue...
I dont think its timing. I think its a no spark condition. Timing off it would kick back or back fire. It would show signs of a spark. Spinning over the same all the time with a random start up is a very weak or no spark deal. Check for spark in both run and start positions. Will it start with a hot wire? I had a car that would not start unless I leaned on the orange box every morning. Yeah, I did the ground thing on it. Never changed that box though, I can be a stubborn *** at times.... . Make sure that battery is fully charged. If that helps you might have a bad connection in the ignition. But, check for spark. Check it at the plug. Needs to be steady as the motor turns over. You will get it right.