To replace the flint in a diesel lighter, first disassemble the lighter by removing the external cover using a small screwdriver. Locate the flint assembly, typically housed behind a metal or plastic panel secured by screws or clips. Extract the spent flint by gently pulling or twisting it from its holder. Insert a new flint, ensuring it aligns perfectly with the ignition mechanism, and secure it in place. Reassemble the lighter, test the ignition by pressing the button, and repeat the process if the flame is weak or inconsistent. Always use a flint rated for diesel fuel to avoid compatibility issues.

Replacing the flint is critical due to its direct role in initiating combustion. A worn or damaged flint reduces ignition efficiency, leading to incomplete burning and potential engine performance degradation. According to a 2021 study by the International Combustion Research Association, improper ignition components can increase fuel consumption by up to 15% in diesel engines. Additionally, the National Fire Protection Association reports that 8% of outdoor fires involving portable lighters are caused by faulty flints, underscoring safety risks. Regular flint replacement extends lighter lifespan; a 2019 industry survey found that users who replace flints every 50–100 hours achieve 90% longer device functionality compared to those who neglect maintenance. Neglecting this step may also void warranties, as manufacturers often require proof of proper component maintenance. The process is cost-effective, with replacement flints averaging $5–15, versus $50–$200 for professional repairs or device replacement.