What is a characteristic of two-stroke engines?

Two-stroke engines are known for their ability to produce more power relative to their size due to their design, which allows for a power stroke to occur every revolution of the crankshaft. This repeated power stroke can create more torque and horsepower compared to four-stroke engines, which only fire once every two revolutions. However, this increased power comes with the trade-off of higher emissions. The combustion process in two-stroke engines tends to be less complete, leading to a greater release of unburned fuel and oil into the environment, which contributes to broader pollution issues.

While other characteristics such as potentially lower weight and simplicity in construction can be associated with two-stroke engines, the defining feature in this context is the combination of resulting higher power output and the accompanying increase in emissions, making this the most accurate choice regarding the characteristics of two-stroke engines.