Any 850a owners notice burnt grass under the muffler? I stopped my machine for about 30 seconds on a couple lawns last week. Well, when I returned this week to those lawns I found burnt grass where the machine sat. The muffler is too low to the ground, I can't wait for leaf season, I will be setting entire lawns on fire. Deere will here about this before the end of the week. Dealer said they have had the same problem on the x540 tractor for a couple of years and no fix yet.