While you are "in the shop" read all of the tech articles on this site, anything from Dr Honda, Lou, Chester, and SeadooSnipe. Download the operators manual...lots of good info in there.
Its def a head scratcher why the carbone ring shattered...maybe from heat? I wouldnt think so but were talking seadoos here stranger things have happened. I see them all the time with chips in them...
When you have a driveshaft spin both the PTO and driveshaft have to be replaced...I had a jetboat guy go cheap on me and wanted to try it...The PTO lasted about a 1/2 tank of gas and wrecked the driveshaft again.
I got all the parts pulled and they are shipping today. Thanks for the biz and we appreciate all the referrals!!! Finally slowing down enough that I can post a bit more again.