Oudy fellas, A mate of mine has had a bit of bad luck with his 06 WR450. Went riding recently and for no apparent reason the bike just stopped. Managed to push start it and it ran for a few minutes, but since then we had no luck. Upon further inspection we've found that the piston has cracked. Its only hanging on by about a 1/4 inch (on the piston skirt). To cut a long story short, the bike is actually an 05 model, however within the first week of ownership the gearbox seized whilst on a transport section (doing 70 mph on bitumen). Luckily he didn't come off. He skidded to a halt and buggered up the rim in the process. Fortunately, Yamaha came to the party and replaced the rim and the entire engine with a new 06 engine under warranty. So my question is this, has anyone out there experienced a similar problem? The bike is well maintained. Its done approx 1300 miles. He doesn't do the maintenance himself, he leaves that to the dealer. He does his oil changes at 300 miles (which isn't quite as often as I would personally recommend) but nevertheless I know many that do theres less frequently. He uses Motul 5100. The bike has always sounded as if it were jetted correctly. It definately does not sound as if it is running lean (no popping). The spark plug showed no signs of detonation either. It was a perfect tan colour. As for fuel, he does not use premium unleaded. Just the standard stuff, which probably doesn't help matters. But having said that, neither do I or most people I ride with. I am a proud 05 WR250 owner. My mates ride YZ 250 / 450s and abide by similar maintenance schedules, using similar fuel, oil, with no dramas. Is my mate just unlucky?