2004-2005 Yamaha Majesty 400 YP400(S) Factory Service Manual (P/N 5RU1-AE1)

• Covers 2004–2005 Yamaha Majesty 400 YP400(S) scooters, including detailed service specifications for the 394.9 cc liquid-cooled DOHC engine and transmission assembly
• Original 100-page OEM publication (P/N 5RU1-AE1), dated December 2003
• Contains 37 exploded-view diagrams and 35 detailed torque tables for engine, chassis, and electrical system fasteners
• This first edition documentation provides the primary build specifications for the 5RU1 and 5RU3 model variants

Component and Systems Overview

This service publication outlines the complete chassis breakdown alongside extensive data on the fuel injection system, automatic centrifugal clutch, and cooling circuits. It provides precise maintenance and adjustment parameters for the front fork, steering head, and swingarm. You will also find electrical system reference values for the A.C. magneto, rectifier/regulator, and battery charging circuit. These specific details streamline routine workshop diagnostics and complex component overhauls alike.

Specification Previews

The manual lists critical technical data essential for daily workshop operations. Valve clearance for the intake sits at 0.15–0.20 mm according to the cylinder head specification table. Radiator cap opening pressure is firmly documented at 110.0–140.0 kPa, while the fuel pump output pressure is specified at 250 kPa. Prioritizing safety in the bay is crucial, as working on high-pressure fuel networks or live electrical circuits carries inherent risks. All service data shown here is for reference only. Always rely on the original OEM documentation as the authoritative source for your hands-on work and ensure you possess the appropriate mechanical training before proceeding.