This is an operator's manual for John Deere 40 series corn heads. It provides detailed information on the operation and maintenance of this heavy equipment. With this manual, you can learn about the specific features of the corn head, such as its brand (John Deere) and model year (1991), and how to properly use and care for it. The manual covers a variety of topics including safety, assembly, adjustments, lubrication, and troubleshooting. It is an essential resource for anyone who owns or operates this type of equipment. Whether you are a professional in the heavy equipment industry or a farmer who needs to harvest corn, this manual will help you get the job done right.