Assuming you have already checked the oil - Check that your connections to the battery are cleaned and tight. Corrosion can build on the battery terminals that leads to poor earthing and slow starter motor. If that is okay check that the belts are not dragging on the pulleys underneath and therefore slowing things down. If all that is okay you need to look at starter motor itself.
Possible poor contacts or dirty on brushes.
epark mowers, February 2009
