Help! I got off my mower to empty the UV today and there was a loud rattling sound and a bad vibration at idle with the brake on. i got back on and accelerated and it was "hopping" so to speak. i jacked it up and started it and saw the hydro to engine tensioner slapping back and forth producing the clanking sound. i shut it down and noticed the belt needs to be replaced (chunks missing all around the belt). It has 830 hours on it and has never been replaced, Lazer Z HP 52" with a 23 kawi (2000 model). any idea if this is my problem? also can you provide me with the OEM part number for the belt? I noticed the tension has a pretty heavy looking spring on it and the deck belt and clutch is below one pulley, do those have to come off too?