This comprehensive service manual covers a range of engines, including the F2L, F3L, F4L, F2M, F3M, F4M, BF3L, BF4L, BF3M, and BF4M series. Engineered for reliability and performance, these engines are designed for various demanding applications. This manual is an essential resource for owners, mechanics, and technicians, providing the detailed information required to ensure optimal operation and longevity of your engine. The scope of this manual is extensive, encompassing all necessary information for the maintenance, troubleshooting, and repair of the covered engine models. It includes detailed specifications, safety regulations, accident prevention guidelines, disposal regulations, operating instructions, and workshop procedures. With clear explanations of symbols, test and adjustment data, and tightening specifications, this manual empowers users of all skill levels to perform maintenance and repairs accurately and efficiently, ultimately preventing premature failure and reducing unnecessary costs.