I estimate the mower has about 600-750hrs and still runs strong. I'm not sure what to do with the engine, it may have another 600 or more hrs left. The mower it is attached to wasn't built to handle my 4 acres, it lasted 8 years with several deck and wheel issues over the past 4 years. Of hate to throw the engine away with the mower, does anyone have suggestions? It is a 2010 720cc 26HP professional series.