A flat-four engine has 4 cylinders arranged in an opposite direction together a common crankshaft. The pistons transfer faraway from each other concurrently. Examples are Honda CB750 and BMW K1200RS. Freehub: a ratcheting assembly onto which a cog or cassette is mounted that permits the bicycle to coast without the https://bike-engines-for-sale38936.humor-blog.com/33964387/a-secret-weapon-for-go-kart-kits