A flat-4 engine has four cylinders arranged within an opposite direction along a standard crankshaft. The pistons move away from one another simultaneously. Illustrations are Honda CB750 and BMW K1200RS. A radial-triple engine has three cylinders organized in the triangle along a common crankshaft. The pistons transfer at different periods https://bikeengineflush15835.ampedpages.com/the-best-side-of-bike-engines-for-sale-61949658