When the engine is completely new, we have rebuilt it or installed some internal component kit, such as pistons, cylinders or big bore kit, we must perform an engine break-in so that the new components fit together.
During the break-in period, new components generate excessive friction and heat, so specific procedures must be followed to ensure the mechanical elements "break in" properly, thereby prolonging their useful life. Likewise, this increased friction between components generates a large amount of metal particle residue, which must be removed with an oil change after break-in.
Although there are many procedures for performing this break-in, most manufacturers and experts recommend two key points to keep in mind: avoid excessive heat build-up and treat the engine gently during this period. I've adapted an excerpt from the break-in recommendations of the renowned American manufacturer S&S Cycle, probably one of the companies with the most knowledge of engines in the world, how to care for them, and especially how to break them in, as they have spent the last 60 years pushing them to the limit in competition:
1. Initial start-up. Run the engine for approximately one minute at 1250–1750 rpm. Do not twist the throttle or subject it to any loads during this period, as the cylinder head gaskets are susceptible to failure at this time (the engine is cold and has not yet expanded). During this time, check that the oil pressure is normal, that oil is returning to the oil tank, and that there are no leaks.2. Turn off the engine and check thoroughly for leaks or other problems. Let the engine cool to the touch.
3. After the engine has cooled, start it again and allow it to warm up slightly. The engine should not run for more than three or four minutes. When the cylinders are warm to the touch (approximately 60°C), shut off the engine and let it cool to room temperature. Follow the same precautions as for initial start-up and continue checking for abnormalities.
4. Repeat this procedure 3 or 4 times. The engine should take a little longer to warm up each time, and the temperature may rise slightly (+15°C). You can increase the rpm slightly, smoothly varying the rpm from 0 to 2,500 rpm on the final cycle. Don't worry too much about the final carburetion/fuel injection settings at this point, because the idle speed and mixture cannot be correctly set until the engine reaches operating temperature. The engine should not reach that temperature during these cycles. After the engine has cooled to room temperature for the final time, it is ready to begin the 1,500-kilometer engine break-in process.
5. The first 80 kilometers are most critical for the piston rings and pistons. Engine damage is most likely to occur during this period. Keep the engine temperature low, not exceeding 2,500 rpm. Avoid overloading the engine, driving in very hot ambient temperatures, or driving in city traffic. Constantly vary the engine speed, but don't overwork it. It is recommended to change the oil after these 80 kilometers.
6. The next 800 kilometers should be driven at no more than 3,500 rpm or 100 km/h (62 mph). Avoid continuous constant speeds and don't overload the engine. Vary the engine rpm.
7. For the remainder of the first 1,500 kilometers, the engine can be used normally, but conservatively. You can be more liberal with the rpm range, and the motorcycle can be operated at normal highway speeds. Avoid overheating or putting excessive load on the engine: no sudden acceleration, dyno tests, excessive speed, etc.
8. After 1500 kilometers, check the injection or carburetor adjustment.
Change the engine oil. It's recommended to use an internal cleaner like Engine Flush before draining the old oil and refilling with synthetic oil. The motorcycle can now be operated normally.
9. Enjoy!
1 comment
En el cambio de aceite a los 80km, sería necesario cambiar filtro también? Saludos.