This is my cleaning process. The video is basically a description of how I go about cleaning with some tips. I show what the machine looks like after each step. I'm a little obsessive about keeping my 299D3 clean and maintained. I recommend checking your air filter frequently if you are working in dusty conditions, they get dirty in a hurry. I also believe it's best to have everything clean prior to changing any of your fluids and filters to avoid contamination.
These machines should last years with clean air, fuel, and oil. Keep it greased every 8 hours and keep the interior clean and it you will enjoy using it everyday with few signs of wear.