Check battery voltage while cranking. The electronis require AT LEAST 10V while the engine is cranking. Less that that, and there will be insufficiant power to pull in the relay that opens the magneto grounding circuit - so no start.
One reason NOT to fit complex electronics to a LAWN MOWER!
phil_saunders(a)bigfoot.com
Phil Saunders
March 2010
Automatic Answer
We may have found other answers which could help you.