The ignition sound of the old logo 307cd player is abnormal.

(1) Due to wear or improper adjustment, the valve clearance is too large, resulting in impact sound. ?

(2) The valve rod end or the valve clearance adjustment screw is worn. ?

(3) The closing gap between the valve stem and the valve guide is too large. ?

2. Diagnosis and failure?

(1) When listening to the abnormal sound outside the valve plug, the rhythm changes with the change of engine speed, and the ignition rings once when the engine temperature changes or the bar is turned off. ?

(2) Fold off the valve cover, select a feeler gauge with appropriate thickness, and insert it into each valve gap one by one to listen for any change in abnormal sound. If the abnormal sound is obviously weakened or disappeared, it can be diagnosed that the valve clearance is too large, and the valve clearance is adjusted according to the abnormal sound. ?

(3) If the valve clearance is normal and the valve still has noise, it means that the valve stem and valve guide are seriously worn and the clearance is too large.