A brief burst of high-speed riding should not cause significant damage to the engine of your Yamaha FZS V3, especially if it was properly maintained and within the operating limits of the motorcycle. However, it's worth noting that sustained high-speed riding can put additional stress on the engine and other components, potentially leading to increased wear and tear over time.
Modern motorcycles are designed to handle short bursts of high-speed riding without major issues. However, it's essential to consider factors such as engine temperature, oil quality, and regular maintenance. If your motorcycle has been maintained according to the manufacturer's recommendations and is in good overall condition, a brief one-minute burst on fifth gear should not cause any immediate damage.
That being said, it's always a good idea to ride responsibly and avoid continuously operating the motorcycle at high speeds for extended periods. Regular maintenance, including oil changes, filter replacements, and overall inspections, will help ensure the longevity and performance of your motorcycle's engine. If you have any concerns about the condition of your motorcycle, it's advisable to have it inspected by a qualified mechanic.