There are several reasons why diesel engines are not commonly installed in motorcycles:
Size and Weight: Diesel engines are typically larger and heavier than their gasoline counterparts. Motorcycles, with their compact and lightweight design, require smaller and lighter engines to maintain proper balance and maneuverability.
Vibration and Noise: Diesel engines tend to produce more vibrations and noise compared to gasoline engines. Motorcycles, especially sport bikes and cruisers, strive for smooth and refined operation, which is better achieved with gasoline engines.
Power-to-Weight Ratio: Gasoline engines generally have a higher power-to-weight ratio compared to diesel engines. Motorcycles prioritize power and acceleration, and gasoline engines are better suited to deliver the desired performance in a lightweight package.
Refueling Infrastructure: Gasoline is widely available at fuel stations worldwide, while diesel fuel may not be as readily accessible. Motorcycles are often used for commuting, and the convenience of refueling with gasoline is an advantage.
Cost and Complexity: Diesel engines are generally more complex and expensive to manufacture compared to gasoline engines. Motorcycles, particularly in the mainstream market, aim for affordability and simplicity to attract a wider range of consumers.
While there have been some experimental and specialized diesel motorcycles developed, they have not gained widespread popularity due to the aforementioned factors. Gasoline engines remain the preferred choice for motorcycles due to their characteristics better suited to the requirements and preferences of motorcycle riders.