There is usually a deck belt and a drive belt.
Castlegarden
Most riding mowers are driven by a belt.
How long is the drive belt
I have Murray 42" cut riding mower that the belt came off. How do I put the belt back on?
You have probably broken the drive belt. With the mower turned off, lie on the ground and look underneath the mower. There is a deck belt and a drive belt. The drive belt is the upper belt. Grab the upper belt and see if it is broken.
Where can we find a simplicity riding mower model 284707 belt diagram
To replace the belt on your Troy-Bilt riding mower, first, locate the belt on the mower deck. Loosen the tension on the belt by disengaging the blade control lever. Remove the old belt and install the new one by following the belt routing diagram in the mower's manual. Make sure the belt is properly seated on all pulleys before re-engaging the blade control lever.
Size of the blade drive belt on a kgro lt4218
maybe your deck is too low
You can change the drive belt, on your lawnmower, by loosening the tensioner pulley. With the tensioner pulley, loosen the drive belt will come off and can be replaced.
On a riding lawn mower, the drive belt(s) goes inside the guide pins.