I demoed a Super Z 60/25 and a 52/20 yesterday. The dealer drove 50 miles in one direction for me to demo these mowers. The SZ is my choice. However when I asked him about the Kohler 28hp EFI engine, he said that he would stay away from the EFI and liquid cooled engines " too many parts to fail". He said that air cooled is the way to go. He also said that he thought the 25hp kaw. was plenty big enough for the 60" deck. I would like to hear from all you guys that use these engines and who have 60" decks. How will these engines hold up after the warranty is gone.(150-200 hours per year) Please help me make a decision on a engine for my Super Z. Thank Cheyenne After mowing my yard, I talked my parents into trying the demos out on their lawn. They are going to the bank today. Seems I may have sold my first Fast-Track and I don't even have my Super Z yet.