chapter 120 Make her convinced

What is the easiest way to repair mechanical products, including motorcycle engines?

The easiest way is to see the faulty part at a glance, then replace it and that's it. However, no one in this world can see what parts are broken inside the engine. Even the most experienced mechanics can only rely on experience to determine which parts are broken and then disassemble and inspect them. But even the most experienced mechanics make many misjudgments. After all, ears and experience...