Small Engines (Lawn Mowers, etc.): mtd yard machine belt, 12a, belts

Question
i have a yardmachine model # 12a-446b729 and the drive belt keeps comming off is there any fix for that.

Answer
Have you looked at the parts list to ensure all the belt guides are in place?  Loose belt, missing/broken or mis-aligned belt guides can cause the belt to come off.

Does the belt come off as soon as you try to drive the mower or does the belt come off every now and then?

Are you using MTD belts?
Let me know.
Eric