Here's a more detailed breakdown:
1. Look for a flat, rectangular surface on the right side of the engine. It should be near the cylinder head, which is the top part of the engine.
2. The engine number is usually stamped into this surface. It might be a combination of letters and numbers.
3. Clean the area if necessary to make the number easier to read. You can use a wire brush or a rag with some cleaner.
If you can't find the engine number in this location, you can check the Yamaha owner's manual or contact a Yamaha dealer for assistance. They should be able to provide you with the location of the engine number for your specific model year.