Step 1
Turn your Troy-Bilt self-propelled lawn mower onto its side, then lower the deck lift lever from the right side of the mower.
Step 2
Locate the belt underneath the mower, then remove the belt guard screws using a Phillips screwdriver.
Step 3
Pull out the belt holder rod with your hand, then you will be able to access the belt tensioner, which is medium-sized metal bolt beside the belt with a square-shaped hole in it.
Step 4
Insert an Allen wrench into the square hold of the belt tensioner. Turn the wrench clockwise to tighten the belt tension.
Step 5
Turn the wrench counter-clockwise to loosen the tension of the belt. Place the belt holder rod back over the belt once you have reached the desired tension for your belt.
Step 6
Reinsert the belt guard screws to the belt holder, then place your back into the upright position.