Mark, it sounds like you have made your mind up and you are going well beyond anything normal here, I have been screwed by every person I have bought a go fast from, thats why I am done unless I can buy new, in my case no one stepped up and these were well know problems that were masked to look good but failed later. Like said, he is now a performance boat owner and better plan on the other motor going and drives going, not because they were abused but because he is a rookie and has no clue to what kind of stress these items see. Whats next with this guy???? Drives? Ginbals? Steering? You better make it clear this is it, he is on his own and that if he so much as nicks a prop he better not come crying back. This just proves his rookieness, to even ask for this to be covered by you is very bold, you could never have seen this and I bet 100% that this is driver error and he was all geeked up after watching Miami Vise and thought he could launch this..difference is these stunt drivers, and yourself, knows when to back off....like when the tach hits 7000rpm in mid air. You are a good person, just don't let him take advantage of this, he has no leg to stand on.