Small Engines (Lawn Mowers, etc.): Yard Works Lawnmower - Belt keeps breaking, burrs, pulleys

Question
Yard Works self-propelled lawnmower - belt keep breaking.  I've replaced 6 belts already.  What is causing the belts to break?????

Thanks

Gilles  (very frustrated)

Answer
Are you useing an OEM belt or aftermarket belt?

What is the mower model number?

Are there any burrs or sharp edged on the pulleys?  Is the belt fraying or just being sliced when it breaks?

Are the pulleys out of alignment?

Let me know the mower model nubmer so I can look up the drive system.
Eric