I have a 2001 Lazer Z HP with about 700 hours on it and I feel like it does not have the power it used to. I noticed it around the time that I had that exhaust upgrade on on the mower. Has anyone else had this problem? Here is a couple of the problems I have been having: 1. Low power (at least is feels that way) 2. Constant clumping of grass when I mow in semi thick grass, even when the grass is dry. 3. Overall not cutting all the grass. 4. Even when mowing at 1 MPH the grass clumps. I have already tried different blade types and everything, but I have just not been happy with the cut quality over the past year. I would greatly appreciate any help or feedback anyone may know about. Thanks.