No, not all motorcycles have engines that are tilted. The engine tilt or orientation varies depending on the motorcycle design and the type of engine used.
In many motorcycles, particularly sport bikes and some standard or naked bikes, the engines are generally mounted in an upright position. These motorcycles often have inline engines, where the cylinders are aligned in a straight line. The engine is typically positioned vertically with the cylinders facing forward or slightly tilted for improved weight distribution and aerodynamics.
For example, cruiser-style motorcycles often have V-twin engines, which consist of two cylinders arranged in a V-shape. In these cases, the engine is typically tilted at an angle to accommodate the V-shaped configuration.
Furthermore, some motorcycles, such as off-road or adventure bikes, have engines that are tilted forward or backward to enhance performance in specific conditions. Tilting the engine can affect the motorcycle's center of gravity, weight distribution, and overall handling characteristics.
In summary, while many motorcycles have upright engines, there are also motorcycles with tilted engines, depending on the design, engine type, and intended purpose of the bike.