I have a 2010 1054. The blades slow down if they even look at "tall" grass. The engine doesn't slow down though. I've triple checked the deck level and height, have been greasing everything diligently since I've owned it plus the idler pivot. I put anti-seize on that and it is free. The spindles are all free and not binding. I put on a new deck belt 2 weeks ago. The only other thing we can think of is the PTO clutch is slipping. Is that possible? I checked the volts at the plug for the PTO clutch and am getting 13.1 volts there; engine running and PTO switch on. Thanks for any help you can give.