Yes, a single cylinder motorcycle engine can go well over 80,000 miles with proper maintenance and care. The longevity of an engine depends on various factors, including the quality of the engine, the manufacturing standards, the type of maintenance performed, the riding conditions, and the owner's care and attention to the motorcycle.
Motorcycles with single cylinder engines are often known for their simplicity and durability. They have fewer moving parts compared to multi-cylinder engines, which can potentially lead to fewer points of failure. With regular oil changes, proper maintenance of the cooling system, timely replacement of worn-out components, and adherence to manufacturer-recommended service intervals, it is not uncommon for a single cylinder motorcycle engine to exceed 80,000 miles and continue running reliably for many more miles.
Of course, individual experiences may vary, and there can always be exceptions based on specific circumstances or issues that may arise. However, with proper care, attention, and maintenance, it is certainly possible for a single cylinder motorcycle engine to have a long and trouble-free lifespan.