Originally Posted by weeze
i have basically the same mower. a z920a. use Oregon G6 blades and you will be amazed at the difference it makes. they are cheaper than stock blades and do a better job and they make the engine bog down less in thicker stuff.
I was just studying up on the blades a few days ago and someone else I believe mentioned trying those...think it was Ridin Green. He also had some tricks to make it stripe better. I haven't had time for playing with it yet, but I hope to soon when things die down a bit.