This TXT file will provide you with a link allowing you to download a PDF of about 100MB. This PDF service/shop repair manual is for a Mercury Mariner 1980 20HP . This manual will show you every nut and bolt on your Outboard. With hundreds of pages, it will show you how to distinguish any problem (from an oil change to a transmission swap) and how to fix it on your own. There are many illustrations to aid you during your job and easy to read text throughout the manual. You will be able to use the search function to browse the manual and print out your needed pages. This Factory Service Repair Manual will guide you through fundamentals of maintaining and repairing, step-by-step, to teach you what the factory trained technicians already know by heart. By applying the knowledge in this service repair manual, any owner will be able to make the right decisions about what they need to do to maintain and repair their machine. - Not only do we guarantee a great quality service manual, but we will also follow up with excellent customer service! Customer Satisfaction Guaranteed!!! For more service manuals visit www.johnsmanuals.com