We regret to note your drive belt jump problem.
You should check the deck adjustments per the Owner's Manual to assure the deck is not too low in the front, and examine the pulleys the belt rides on to see if any misalignment can be seen.
Also be aware that, if you may be mowing in the lower deck settings, and the lawn is uneven, the anti-scalp wheels may be contacting the ground in such a way that the deck is frequently "bouncing"; that condition can also contribute to belt retention problems.
If you are unable to find the cause of that condition, we can only suggest you have your service dealer evaluate the unit to determine why the belt jump is a problem.
We trust the above is helpful.
It's not the deck belt that is jumping off it is the drive belt, the one that powers the two hydrostatic pumps to provide power to the drive wheels.
We regret to note your drive belt jump problem.
You should check the deck adjustments per the Owner's Manual to assure the deck is not too low in the front, and examine the pulleys the belt rides on to see if any misalignment can be seen.
Also be aware that, if you may be mowing in the lower deck settings, and the lawn is uneven, the anti-scalp wheels may be contacting the ground in such a way that the deck is frequently "bouncing"; that condition can also contribute to belt retention problems.
If you are unable to find the cause of that condition, we can only suggest you have your service dealer evaluate the unit to determine why the belt jump is a problem.
We trust the above is helpful.