I have an 250xs optimax with about 220 hours. Six hours into tournament saturday running WOT at 5900 motor started making a bad rattling noise and slowing down when i set boat down off plane the motor had a terrible vibration. I thought she had blown up. Shut it off, then started it back up motor sounded fine shifted into gear and liked to shake the windsheilds off. Pulled cover off thinking commpressor was gone. Alll looked good no bolts broke and belt on compressor still looked good. Got home and pulled prop and drained lower unit oil and nothing but shavings. No signs of water oil still was blue mercury prem plus. Just was wandering possible what could have happened? What would be the best fix? I have no warrenty left. Do new lowerunits come with a warrenty or should i try and have the old one rebuilt with possibly a 30 day warrenty? Wish i new which way to go. What would the price of a new lowerunit? Torgue master with 1.75 gear ratio.