haha same happened to my old engine :( rebuilt top end rebore barrell and new tzr 0.5m piston and ran it in a good 500 miles then couple months later starter motor went so i bumped the bike for about a month then drove home from work turned left at a roundabout about 15mph then spulter spultter nd engine cut out :( i just payed £350 for a 2007 dt engine wit only 4000 miles done was sweet s a whistle save hassle of trying to repair old engine and my flywheel just jammed on and i managed to un jam it then bump start and same horrbile noise coming from bottom end so justs witched it off and cryed lmao