This is a OEM Service Manual for a Yamaha EF4000DM EF5200DM EF6600DM Contains all the information you need to repair and perform routine maintenance on your generator. Its published by Yamaha and model specific to your bike unlike many aftermarket manuals. Features information such as torque specs, cable routing, electrical diagrams and troubleshooting some problems/issues. EF4000DEM EF5200DEM EF6600DEM