Automatic transmission motorcycles, especially those with 110cc engines, are increasingly in demand by the public because of their practicality. The performance of this motorcycle is greatly influenced by the transmission system, especially the Drive pulley and Roller components. The correct setting of the Drive pulley angle and Roller mass can improve engine performance and reduce noise, thus supporting driving comfort. This study aims to analyze the effect of variations in the Drive pulley angle and Roller mass on engine performance, in terms of power (HP), torque (Nm), and noise level (dB) at several engine speeds. The variations tested include the Drive pulley angle of 13.5°–14° and the Roller mass of 13–15 grams, with testing at 5000, 6000, 7000, and 8000 RPM. The test results show that the combination of the angle and Roller mass affects engine performance. At 5000 RPM, the combination of the 14° angle and 15 gram Roller produces the highest power, torque, and noise. At 6000 RPM, the combination of 13.8° and 13 grams produces a maximum power of 6.86 HP and 8.15 Nm of torque, with a noise of 97.40 dB. While at 7000–8000 RPM, the combination of 13.5° and 15 grams provides the best performance with 7.10 HP and 6.30 Nm of torque, accompanied by a noise of 104.17 dB. In general, increasing the angle and mass of the Roller increases performance, but is followed by an increase in noise.

Internal combustion engines generate thermal energy through the combustion of an air-fuel mixture. The incoming air must be filtered, as it contains impurities and particles. While air filters are commonly made from paper, they can also be developed using organic waste materials such as sugarcane bagasse and rice husk. This study aims to analyze the effect of biocomposite air filters on engine power, torque, and specific fuel consumption (SFC), by varying the material composition and the number of pleats, and comparing the results with those of a standard air filter. The method used is a quantitative experimental approach involving dyno testing on a 150 cc motorcycle engine. The tested material compositions include 50:50, 40:60, 30:70, 60:40, and 70:30 (sugarcane bagasse\:rice husk), with pleat counts of 28, 26, and 24. Results showed that the biocomposite filter with 28 pleats and a 30:70 composition delivered the best performance, producing 18.47 Hp and 16.66 Nm of torque—higher than the standard filter’s 17.98 Hp and 15.52 Nm. In terms of fuel efficiency, the 26-pleat filter with a 50:50 composition recorded the lowest SFC at 41.90 g/kWh, significantly better than the standard filter’s 53.03 g/kWh. Conversely, the 60:40 composition resulted in the highest SFC due to increased airflow resistance.