The wire ring you are referring to is the Wrist Pin Retainer wire.. That has been a problem with these engines and that why CEN will replace it. I have seen this problem before and it almost always happens during break-in. At the time of assembly the wire is not seated completely in the groove and when the engine is started and warmed up the wire comes loose and always gets hung up inside the exhaust port.. Just do what they suggest and send it in and they will send you a new engine.. No fault of CEN's as they buy these engines from a third party supplier..