At the Bloomsberg race on Sunday, my brother was running my pro-x and while going down a straight away, the mower shut off and wouldn't start back up. I thought it was a battery issue, so I got a new one, and it wasn't the problem. I checked all of the connections and they are all tight. You can turn it over by hand, and when you turn it off the compression stroke, the starter will turn it back over till it hits the compression stroke again. Would this be a flywheel key issue? Or should I look deeper? Thanks