Yamaha Bruin 350 ATV 2003–2008 Service Manual Set (P/N LIT-11616-17-33)

Yamaha directs technicians to use the supplement with the base manual. The referenced shared procedures are included in this file, while the supplement supplies the changes and specifications needed for the 350 application.

Model distinction: The liquid-cooled engine, radiator data, front differential and on-command 2WD/4WD system belong to the YFM400FAR base reference. For the Bruin 350, follow the YFM350AS specifications and supplement changes.

PDF Search, Bookmarks and Wiring Detail

Navigation and small labels: Searchable text and embedded bookmarks cover both publications. Small wire-color codes and connector labels require zooming. The cooling-system circuit overview has cropped background wiring at its lower edge; the complete YFM350AS wiring diagram is included at PDF p. 481.

The 481-page printable PDF contains both publications in one file: the base reference at PDF pp. 1–364 and the supplement at PDF pp. 365–481. The total includes 22 pages of front matter, two manufacturer imprint pages and two complete wiring-diagram sheets.

Engine, CVT and Electrical Service Coverage

These selected service topics summarize the repair coverage rather than reproduce the full contents. Further subjects include air-filter cleaning and spark-arrester maintenance.

• Engine repair: Engine removal, cylinder-head and valve work, cylinder and piston inspection, timing-system installation, crankshaft service and recoil-starter repair.

• Fuel and lubrication: Carburetor disassembly, float and fuel-level adjustment, balancer-gear inspection, oil-pump service and oil-cooler removal and installation.

• CVT and transmission: Primary and secondary sheave disassembly, clutch inspection, crankcase separation, internal transmission checks and model-specific reassembly procedures.

• Shaft-drive setup: Middle drive and driven gear shim selection, rear final-drive positioning, bearing replacement and gear-backlash measurement and adjustment.

• Brakes and chassis: Front brake hydraulic service, rear drum-brake repair, wheel and bearing checks, steering-stem service, tie-rod work and suspension inspection.

• Electrical diagnosis: Starting, ignition, charging and lighting tests, oil-temperature warning checks, fan-control troubleshooting, circuit diagrams and the complete YFM350AS wiring diagram.

Written primarily for Yamaha dealers and qualified mechanics, these publications assume an understanding of mechanical principles and machine-repair procedures.

Engine, Carburetor and Lubrication Work

Step-by-step instructions support top-end inspection and assembly, including valve guides and seats, piston rings and camshaft timing. The supplement adds the 350-specific component layouts and service data used alongside those procedures.

The carburetion chapter covers the Mikuni BSR33, including diaphragm, needle-valve and jet inspection. Its float-height and fuel-level procedures provide the adjustment context for the carburetor specifications.

Balancer-gear and oil-pump job charts identify the components, replacement items and lubrication points. Oil-capacity tables distinguish periodic changes, filter replacement and total engine capacity, with separate final-gear quantities; the Oil Flow Diagrams and Cable Routing drawings show the associated passages, hoses and leads.

Cylinder-head bolt sizes and tightening specifications differ between the two publications; applying the base manual’s head-bolt values to the 350 can over-tighten its fasteners.

Sheaves, Crankcases and Gear Setup

The Primary and Secondary Sheaves exploded views are paired with job charts showing removal order, quantities, lubrication points, thread-lock locations and torque callouts. These give a technician the component sequence and inspection data needed for disassembly and reassembly.

The supplement also supplies its own crankcase and transmission layouts. Assembly checks address shift-fork placement, free gear rotation and transmission operation before the crankcase fasteners are tightened.

Selecting the Middle Drive and Driven Gear Shims uses component and housing markings to calculate shim thickness. Replacing a gear, bearing housing or crankcase requires renewed shim selection; incorrect spacing can damage the gears and bearings.

Listed tools include the YU-90050 crankshaft installer set and YU-01135-A / 90890-01135 crankcase separating tool. Secondary-sheave service calls for the YM-04134 / 90890-04134 spring compressor, YM-04135 / 90890-04135 fixed block and YM-01348 / 90890-01348 locknut wrench.

Brake, Steering and Electrical Diagnosis

Chassis tables supply brake wear limits, wheel runout, toe-in, suspension travel and fastener torques. Model-specific rear brake, steering-stem, tie-rod and front-arm job charts supplement the shared procedures.

Troubleshooting addresses hard starting, poor idle or high-speed performance, clutch slipping, no-move complaints, hard shifting, jumping out of gear, overheating, weak braking and unstable handling.

Electrical tables provide charging output, regulated voltage, ignition- and charging-coil resistance, starter-motor inspection dimensions and fuse ratings. The Signal System Circuit Diagram supports warning-light and diode checks, while the YFM350AS Wiring Diagram identifies components, connectors and wire-color codes.

The supplement’s Cooling System section concerns the oil-cooler fan, fan relay, thermo unit and oil-temperature warning circuit. It includes component tests and thermo-unit resistance checks at specified temperatures.

Support the ATV securely before chassis work, follow Yamaha’s warnings and specified torque values, and use the correct service tools. Brake, steering, CVT, electrical and internal-engine repair should be performed only by someone with the mechanical knowledge assumed by the publication.

A Preview of Valve, Clutch and Gear Inspection Data

For YFM350AS valve-clearance checks, the cold-engine ranges are 0.06–0.10 mm intake and 0.16–0.20 mm exhaust. The automatic centrifugal clutch tables give a clutch-shoe wear limit of 1.0 mm and an engagement range of 1,950–2,350 rpm.

The shaft-drive specifications list middle-gear backlash at 0.1–0.3 mm and final-gear backlash at 0.1–0.2 mm. These accompany the gear inspection and adjustment coverage rather than replace the complete procedures.