Yamaha motorcycle engine you need to know what size it is the number on case 1nh-001405?

Unfortunately, the number "1NH-001405" alone doesn't tell us the engine size. This is likely a part number for a specific component of the engine, not a code for the entire engine size.

To figure out the engine size, you'll need more information. Here's what you can do:

1. Find the engine model: Look for the model name or code on the motorcycle itself or in the owner's manual. It will likely be something like "Yamaha SR400," "Yamaha R6," etc.

2. Search for the model online: Once you know the model, search for it online (e.g., on Yamaha's website or motorcycle forums) and look for specifications. The engine size will be listed there.

3. Locate the engine displacement: If you can access the engine itself, look for a sticker or marking on the engine case that states the displacement (e.g., "125cc," "400cc," etc.).

By finding the engine model or displacement, you can determine the engine size.