Premium material: the high-quality aluminum, iron, and plastic material give it good hardness, wear resistance, and durability, allowing for long-term use. enjoy riding: this kit converts your bike into a motorized bicycle, with max. speed of 3600rpm for great efficiency and convenience, allowing you to fully enjoy the fun of riding on your commute and short journeys. high performance: the 4-stroke engine is more stable, more reliable, and quieter than the 2-stroke engine. also, the 56mm bore cylinder increases the bearing capacity, and reduces the working temperature, making it easier to start, while providing continuous output over a range of speeds. 4 stroke bicycle motor kit
