I have an awesome 2005 KX 125 but it has an engine rattle that is driving me nuts! It has a new top end with a Pinsonnault 144cc kit, but it was rattling before I installed it. It only rattles while accelerating. It doesn't do it while just sitting still and revving. Have replaced the clutch bearing. Clutch basket has very little wear. Doesn't seem to affect the performance any. Shifts great. Excellent power and compression. Any ideas? Power valve issue??