The O.S. Max warranty covers defects in parts and workmanship of the original manufacture of the engine for a period of two years from the date of original purchase to the original owner. If you believe you have a difficulty that would come under the warranty, please send the engine to us. Please see the "sticky" thread at the top of the O.S. Max forum for details, or see the web page:
http://www.hobbyservices.com/