I have been dealing with poor cuts for about two weeks now. Been trying everything to make it cut better so I bought a brand new set of JD fatory high lifts for my JD 777 60 in. and it's still leaving rooster tails everywhere. Same w/ every other type of blade that I own. Leveled the deck, air pressure, no build-up underneath and I don't mow that fast to begin with. The only way it cuts nice is to move along at a snails pace. My question is do I need to replace the belts too???They are about a year and a half old. Thanks for your responces.