1450 w/44A Deck Drive Belt Problem
 

I've been using NAPA 4L79OW belts for a number of years with mixed success. Sometimes they last a year or two but sometimes I'll need two for a season of mowing. I guess it depends on how many rocks I hit. I just put on a new belt and noticed the V flips upside down (i.e. V up) when it gets up to the PTO pulley. It then turns V down (correct position) as it goes down and passes through the mule pulley, back to the deck drive pulley, and forward through the second (spring-controlled) mule pulley. As it heads up to the PTO it flips over to V up attitude to start the cycle again. All pulleys are free and true, and the belt tension is correct i.e. forward notch in the spring controller is lined up with the front carrier cross bar in accordance with the decal showing correct tension. I tried realigning the belt but as soon as I turn on the PTO it flips. Still seems to mow fine but I'm sure it doesn't add to belt life. Anyone know cause and solution for "flipped belt"?

One problem might be that you aren't using the OEM belts that are designed for all of the twisting and turning. Not all belts are created equal.