I had a guy come rent an ATV from me tonight and he said that he was thinking of getting a YFZ, but he had heard from a reliable source at a local dealer (I know who it was and he is pretty reliable, however not a Yamaha dealer) that said he's talked to a couple of people who have had engine problems, but had no specifics. I was just wondering if anybody has had any engine problems of any sort?? I have had my machine for 3 months now and I motocross it quite a lot and I also rent it out and have not had a single problem. Anyone??