Unit was running great, it suddenly started making a loud growling sound and huffing black smoke. Air filters are recently new, unit has 1180 hrs. What to look for.
Black smoke is over fueling for the engine rpms its running. Your growling is something dragging the engine speed down. This could be several things. Is this machine at 1180 hours still under warranty? You might want to supply the machine serial number also.
Is it running poorly or acting like it's overloaded?