Larry,

Exactly where I hooked in the "C" lead to the system I don't have a perfect remembrance of - I'll have to take a look next time I am out. I think I hooked it to the bus near the battery lug after the master solenoid so it is cut out when the master switch is off - BUT - I'll have to look

The book John suggested is great - between that and the Rotax installation manual - you'll get done

Enjoy your build