I purchased a new TT with a 26.5 EFI about a month ago and only have 25 hours on it now. I was mowing a large yard when it had a total lose of power due to a rocker arm coming loose. Come to find out from the dealer that there's a service bulletin on this issue and both sides had to be tightened down using more torq. Anybody that has this engine needs to check into this. Or if you're gonna buy one better ask questions.