Which of the following is NOT a characteristic of four-stroke engines?

Four-stroke engines are designed in a way that typically results in reduced emissions and higher fuel efficiency compared to their two-stroke counterparts. This is largely due to the fact that four-stroke engines complete a power cycle in four separate strokes of the piston, allowing for better fuel atomization and combustion, which leads to cleaner exhaust.

The complexity of the design is another distinguishing feature of four-stroke engines. They incorporate additional components like valves and camshafts that are necessary for the intake and exhaust processes, making them more intricate than two-stroke engines, which generally rely on simpler mechanisms.

In contrast, regarding weight, four-stroke engines are often heavier than two-stroke engines. This weight difference is primarily due to the added components and mechanisms required for the four-stroke cycle, along with a more robust construction to handle the increased pressures and operating conditions.

Therefore, the statement that often claims four-stroke engines are lighter than two-strokes is incorrect, which highlights the misconception regarding their physical characteristics.