This manual covers the Mercury Mariner 115 EFI outboard motor, a 4-stroke engine featuring Electronic Fuel Injection (EFI) and a horsepower output of 115. Designed for reliable performance, this model has been available since 2001, identified by serial numbers starting with 0T178500. Its robust engineering ensures dependable operation for various marine applications, reflecting Mercury's commitment to quality and innovation in outboard propulsion. This comprehensive Service Repair Manual provides essential information for the maintenance, diagnosis, and repair of your Mercury Mariner 115 EFI. It includes detailed procedures for all maintenance aspects, electrical systems, EFI troubleshooting, powerhead, mid-section, and lower unit components. Additionally, it covers attachments, control linkage, and features color diagrams to assist owners, mechanics, and technicians in keeping the outboard motor in optimal working condition.