Rapid progress is being made in the field of science and technology, particularly in the automotive industry, specifically in electric fuel injection (EFI) motorcycles. To optimize engine performance in fuel-injected motorcycles, fuel injection into the combustion chamber needs to be optimized. One approach to achieve this is by adjusting the fuel injection duration using aftermarket programmable Engine Control Units (ECUs). This research aims to address this issue. The study focuses on investigating the effects of varying fuel injection durations on the performance of a 110cc FI (Fuel Injection) Beat motorcycle engine. The variations considered include +5%, +10%, +15%, -5%, -10%, and -15% changes in fuel injection duration. The parameters of interest are torque, power, and specific fuel consumption. The tests were conducted using Pertamax fuel. The results of the tests revealed that a -5% change in injection duration produced the highest power output of 7.5 HP at 4122 rpm. Meanwhile, a +5% change in injection duration resulted in a torque value of 18.94 Nm at 2468 rpm. Furthermore, the testing showed that the lowest specific fuel consumption was recorded at 0.018 kg/kWh at 4000 rpm for a -15% injection duration, whereas the highest specific fuel consumption of 0.119 kg/kWh occurred at 8000 rpm for a +15% injection duration.