A downloadable Yamaha 115 horsepower outboard repair manual is a digitally delivered book of instructions that details the action of fixing or mending a boat motor back to factory specifications.
It’s a handbook that covers every aspect of repair, from basic outboard maintenance to complete engine overhaul. It also contains specifications, troubleshooting guides, as well as pictures, illustrations and diagrams to make the repair process go smoothly.
Contents of a Repair Manual
As with all marine repair manuals, a 115hp Yamaha begins with a cover page and table of contents. The table of contents is located to the lefthand side of the repair manual and contains a list of hyperlinked titles that navigates the user of the manual to other parts of the file.
The hyperlinked titles that make up the table of contents are chapters and subchapters that navigate the user to deeper pages within the document. Here is a list of chapters often found in a repair manual:
1. General Information
The general information section of a manual typically includes knowledge about the main features of boat engine, such as identification number locations, recommended fuel and engine oil types, as well as engine specifications, propeller size charts, tightening torques and other service data.
2. Periodic Maintenance
The periodic maintenance chapter discusses maintenance that must occur at regular intervals so as to extend the life of the motor. The maintenance section in a repair manual contains maintenance schedules and charts. Which detail maintenance and tune-up procedures, such as idle speed adjustment, ignition timing, tappet clearance, fuel pressure, and water pump maintenance—and more. It’s also the section that generally discusses cylinder compression and oil pressure testing procedures.
3. Engine Control System
One of the sections found in a 115 hp Yamaha repair manual is the engine control system chapter. This section lists the engine control system structure and how it performs the control function for fuel injection, idle/trolling speed, ignition, etc. through the engine control module (ECM). It also contains servicing and testing procedures, trouble codes, diagrams and a troubleshooting guide to trace and correct faults within the engine control system.
Every Yamaha repair manual contains an electrical section. This part of the book details the repair, testing and troubleshooting process for the engine’s electrical components. This section outlines the charging system, as well as part inspection, testing, removal, installation, disassembly and assembly procedures. Topics often covered in this section are the battery charging system, electric starter system, starter motor, monitor-tachometer and electric parts holder.
5. Fuel System
The fuel system chapter, as with all other chapters in a repair manual, covers ever aspect of fuel system repair; e.g. inspection, testing, removal, disassembly, assembly and installation procedures. This includes step-by-step servicing procedures of fuel lines, fuel vapor separator, high/low pressure fuel pump, fuel injector and fuel tank. A fuel system troubleshooting guide is also included.
6. Power Unit
The power unit section details step-by-step repair information for the engine’s powerhead. It contains removal, installation, disassembly, servicing, reassembly and installation information regarding the intake manifold assembly, power unit, cylinder head, cylinder, crankshaft, piston, etc. It also provides a visual outline of the water cooling and engine lubrication system operation.
7. Mid Unit
The mid unit section of the manual details routine inspection and maintenance of the outboard’s midsection. It also discusses the process of servicing and repairing the driveshaft housing, oil pan, swivel bracket, steering bracket, clamp bracket, water pressure valve and more. And as with all sections, it contains inspection, removal, disassembly, assembly and installation procedures. Most importantly, this section contains part diagrams, which illustrates where ever part, bolt and gasket goes on the mid unit.
8. Power Tim & Tilt
The power trim and tilt (PTT) unit is a electro-hydraulic mechanism that angles the outboard machine via trim and tilt function. While these components are mostly reliable, they sometimes break. Fortunately, a manual contains a power trim and tilt section that discusses principles of operation, as well as oil level, air bleeding, power trim motor, relay and switch servicing. The 115hp Yamaha manual contains power trim and tilt wiring diagrams in it too.
9. Lower Unit
The lower unit section of the repair manual covers complete removal and disassembly, as well as inspection, assembly and installation of the pinion bearing, propeller, gear case, propeller shaft, gears, driveshaft, driveshaft oil seal housing and more.
10. Wire / House Routing
The wiring and hose routing section of the manual uses detailed illustrations and diagrams to show hose routing and electrical wire routing. It also labels the purpose of the hose/wiring and lists wire colors. Since the repair manual is in digital format, the manual can be zoomed in to make out any fine print.