Sound characteristics of connecting rod big head bearing: when suddenly accelerating (from idle speed to medium speed), there is obvious continuous knocking sound (rolling bearing is accompanied by abnormal noise inside the engine), which is the main feature of connecting rod big head bearing sound. When the big end bearing of connecting rod is seriously worn (loose), there is obvious sound when the engine is idling, and the sound will be aggravated when the load increases.
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Precautions:
There was a lot of oil and dust accumulated on the engine shell during overhaul. If it is not cleaned in time, these impurities will be mixed into the engine body when disassembling the engine. After installation, it will bring unnecessary wear and tear to related components. In addition, foreign matter will fall into the engine, blocking the oil circuit, leading to poor lubrication, resulting in cylinder locking, shaft locking and clutch sintering.
In addition, if the engine shell is not cleaned cleanly, there will be foreign objects stuck at the joint of the box, which will affect the sealing and cause oil leakage and oil leakage. Cleaning the engine housing can also prevent sludge from covering the bolts and avoid leakage. For example, the two fixing bolts in the middle box of Chongqing 80 engine are easily covered with sludge. If they are left outside and the package is forcibly opened, the engine box will be damaged.
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Quality problems of Hunan Wanghong indulgence brand motorcycle