Small Engines (Lawn Mowers, etc.): Lawmower slow in low gear, yardman lawnmower, variable pulleys

Question
I have a yardman lawnmower(3 years old). I noticed last year that in low gear(1 or 2), it would move slowly. If I was going up a very slight incline, it would stop and not move. It even does this when making a turn. My yard's incline is not steep at all. When I shift it to a higher gear, it will move. When I got the mower ready for this year, it is doing the same thing as last year.  It seems to be progressing worse as I have to put the gear in fourth to get it to move when it is stopped.If I am on a straight slope, it is fine, but any kind of incline(the slightest incline) it will stop moving. The engine sounds fine.
Thanks Jamie

Answer
Jamie, alot depends on the type of drive you have.  If its like the MTD's, you have a dual belt drive that uses a set of variable pulleys to change speed.  In this case, you are about to experience a belt failure, its wearing and getting narrower, thus producing lower speeds.  If you have a hydrostatic drive (there will be a cooling fan on top of the rear transmission)  you'll need to check the fluid level.  Let me know if this helps!