I have a DF70, in December of '02 it broke the oil pump drive (50 hours on it). Warranty repair, down for the whole holiday period of course. Then the replacement powerhead failed, 3 hours on it, seized the cam (I suspect improper assembly). The new power head has 20 hours on it, so far so good. The engine was down December to March, I was peeved, 2 fold, it was down, and it is a known factory defect, no effort to find and fix the engines prior to failure (2 hour return trip on the kicker engine). DF 70 is the only engine I have heard much about with trouble, but it was a certain series of engines. To compensate me for the wait the factory gave me a brand new spare Suzuki prop. Mine is smooth, insta-start, quiet and cheap to run. You can do a search on thehulltruth.com, there is a lot of engine talk there, you will find examples of bad engines there, every make, 2 stroke/4 stroke alike. Might note that the Suzuki 90 has EFI and the Merc/Yam90's are carbureted, I like the EFI.