If it needs only two strokes to complete a cycle, it is called a two-stroke cycle engine or, for short, a two-cycle engine.

如果发动机完成一个工作循环，只需要两个行程，就称为两冲程循环发动机，或者简称两冲程发动机。

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A two-stroke engine has no moving valves, and the spark plug fires each time the piston hits the top of its cycle.

二冲程发动机没有移动的阀，火花塞每次点火活塞到达循环顶端。

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Otto built the practical four-stroke internal combustion engine called the "Otto Cycle Engine, " and as soon as he had completed his engine, he built it into a motorcycle.

奥托制造了第一台实用的四冲程内燃机，叫做“奥托循环发动机”，并且当完成制造他的发动机后他就把发动机安装在摩托车上。

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For years he had contemplated the inefficiencies of the traditional four-stroke Otto cycle engine (named for its 1876 developer, Nikolaus A. Otto).

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