Purchased Z127 June 2013 and mower has 210 hours. When running mower (blades engaged or not) every now and the the mower will shut down. I quickly put the handles out to the start position and it comes right back strong. After repeating this move with the handles two or three times the mower does great for a couple of hours and then does it again.Have not replaced fuel filter but have changed oil,air filter per manual. First time here guys so take it easy on me.