What is the difference between inline single-cylinder four-stroke and single-cylinder four-stroke?

[McKaden]

In an inline single-cylinder engine, all cylinders are arranged side by side in a single plane. It features a simple cylinder block and crankshaft structure, uses a single cylinder head, has low manufacturing costs, high stability, good low-speed torque characteristics, low fuel consumption, and a compact size, making it widely applicable. The downside is relatively lower power output. 1. Single-cylinder four-stroke: A single-cylinder four-stroke engine refers to the four working cycles of normal engine operation: intake stroke, compression stroke, power stroke, and exhaust stroke. 2. Inline four-stroke: The movement sequence of the four pistons in an inline four-stroke engine is such that cylinders one and four move together, as do cylinders two and three. For instance, when piston one moves downward for intake, piston four is necessarily in the power stroke, while pistons two and three move upward—one compressing and the other exhausting.