Twin cylinder

From CycleChaos

A Twin cylinder motorcycle is distinguished from other engines by having two driving pistons and connecting rods to the engine's drive shaft. The cylinders operate with one piston at the top of a stroke while the other is at the bottom of a stroke whether in a two stroke or four stroke engine thus creating a engine balance. Twin cylinder motorcycles can have a single or dual exhaust system. It can be four stroke or two stroke in configuration. In some instances a two cylinder, two stroke can have 2 spark plugs with only one active.

Types

• Straight-two: has its cylinders arranged in a single row. It is often improperly referred to as a "straight twin". A true straight twin (or parallel twin) engine uses a common crank pin for both cylinders (small displacement Honda, Triumph).
• V-twin: has the cylinders are arranged in a V configuration (Harley, Ducati, large displacement Honda).
• Boxer twin: two cylinders arranged on opposite sides of the crankshaft (BMW).