Hello everyone. I have a Stihl FS56 trimmer. It was bought new last year and is 10 months old. It was bought with their Motomix feul and that is all that has been used in it. The unit was stored with no fuel in the tank and it was run out of fuel before storage. Today I put fresh Motomix in it and it fired up first pull. It was used for about ten min of work. While under load with my finger on the trigger and cutting away....it just stopped running. When I tried to restart it I could not pull the starter rope at all. I took the spark plug out and still could not pull the rope. I pulled off the cover and starter rope unit and it works just fine....BUT I could not turn the engine where the starter rope connects. Did I blow up the engine in my trimmer? How can I test for problems without voiding the warranty? Buying the Motomix doubled the warranty when I bought the unit. If I did blow up the engine, will it be fixed under warranty? Thanks for the help.