I recently demoed an Exmark Navigator at my local dealer. I noticed that when I would shut the machine off it would backfire almost every time I shut it off. I didn't think much of it because it was the demo unit even though it was a brand new machine. I purchased that same machine about a week later and have now been using the machine for approximately a month. It has still been backfiring quite a bit but I always forget to ask my dealer why that would be happening. What made me thing to post my question is that while I was cutting today a customer approached me with a question and when I stopped the machine it backfired and he nearly hit the ground because he thought he was getting shot at. Does anyone have any experience with this problem or any ideas how to stop this? On a side note I was not the biggest fan of this mower when I demoed it last year but it has really grown on me as I have been using it. So if anyone has been on the fence about purchasing one and you have any questions about my likes or dislikes feel free to ask.