What are the symptoms of a damaged motorcycle cylinder?

[LondonLee]

The engine's temperature rises abnormally, causing abnormal thermal expansion of the cylinder and piston, leading to severe wear or seizure issues. Foreign objects entering the cylinder, such as a dislodged piston pin, can cause severe scratches on the cylinder wall. Insufficient engine oil can result in "dry friction," and in severe cases, "cylinder seizure" may occur. Below is relevant information: 1. Cylinder: Cylinders come in 2-stroke and 4-stroke types, with 2-stroke cylinders commonly used in motorcycles, chainsaws, lawn mowers, and other machines. 2. How a cylinder works: Generally, for the same displacement, more valves lead to better intake and exhaust efficiency. Traditional engines typically have one intake valve and one exhaust valve per cylinder. This two-valve configuration is relatively simple, cost-effective to manufacture, and easier to repair. For ordinary engines that do not require high output power, two valves can provide satisfactory engine output power and torque performance.