For your Yamaha FZ-s v3 motorcycle with 12,500 km of running, it is recommended to use engine oil with the viscosity grade of 10W-40, which is what you previously used. Liqui Moly 10W-40 is a good choice for your bike and should work well.
As for the maximum distance you can run, there is no specific limit for how many kilometers you can ride your motorcycle. However, regular maintenance and servicing are crucial to ensure its longevity and performance. In general, motorcycles like the Yamaha FZ-s v3 are built to handle long-distance rides without any issues, especially if you maintain them properly.
Since you drive 40 km in a single run every day, it's considered normal usage and should not pose any problems for your motorcycle. Going for longer rides, such as 300 km, is also within the capabilities of your bike, as long as it is well-maintained and in good condition. It's a good practice to check the oil level and other fluid levels before embarking on longer rides to ensure everything is in order.
Remember to follow the manufacturer's recommendations regarding oil change intervals and other maintenance tasks mentioned in the owner's manual. Regular servicing, including oil changes, filter replacements, and overall inspections, will help keep your Yamaha FZ-s v3 running smoothly and reliably for a long time.