60" Lazer Z Kawasaki FH770D 28HP intermittent missing

Mower will miss really bad and have loss of power. It sometimes will clear itself and run fine. I have noticed when I run it for awhile and turn the PTO off it will always miss when I re-enguage it. It will also start missing if I load the motor up through tall grass. It has also starting missing when I made a fast sharp turn. If I idle down the throttle and let it sit for a while then re-enguage the PTO it sometimes clears the miss and runs normal again. I changed the fuel filter and removed the air filters and it didnt make a difference. Any thoughts on what could be causing this. Model LAS28KA604 Serial 776602

To me sounds like you have a wire grounding out. I would stat by checking all your wiring. Especially anything running along metal.