The exhaust temperature of a four-stroke motorcycle engine can vary depending on several factors, including the engine's design, fuel mixture, load, and operating conditions. However, as a general range, the exhaust gas temperature of a four-stroke motorcycle engine typically falls between 400 to 900 degrees Celsius (750 to 1650 degrees Fahrenheit) under normal operating conditions.
The exhaust gas temperature tends to be highest during heavy acceleration or under high load conditions when the engine is working harder and generating more power. During these instances, the exhaust gas temperature can reach the higher end of the range mentioned above.
It's important to note that these temperature ranges are approximate and can vary significantly depending on various factors. Additionally, exhaust gas temperatures can rise significantly during malfunction or incorrect operation of the engine, such as fuel mixture problems, ignition timing issues, or problems with the cooling system. Monitoring and maintaining appropriate exhaust gas temperatures are crucial to ensure optimal engine performance and prevent damage to the engine or exhaust components.