SELOC Marine tune-up and repair manuals provide the most comprehensive, authoritative information available for outboard, inboard and stern-drive engines, as well as personal watercraft. SELOC has been the leading source of how-to information for the marine industry since 1974. Designed and written to serve the needs of the professional mechanic, do-it-yourself boat enthusiast, instructor and student, these manuals are based on actual teardowns done by Seloc's editors/authors in our on-site facility. This manual covers all Mercury and Mariner 2.5-225 Hp 1-4 cylinder, V4 and V6 2-stroke models. Only Seloc manuals include Skill level Ratings (1 - 4 wrenches) based upon the degree of difficulty along with Special Tool icons where a OEM or electronic testing tool is required to perform the specified procedure. Over 1,000 illustrations.