Motorman, the conrod broke at the end that was holding onto the piston. It just cracked open. I'm not running the engine lean or anything like that. The conrod feel very weak. I wonder if there are any other conrod that would fit the sirio. I heard the Nova Carbs fit the Sirio, what about the conrod??

The sirio is a great engine in terms of peformance, but they need to sort out their reliability.