Yamaha YFM40FB (Big Bear 400) Service Manual

Yamaha Big Bear 400 Service Manual Features

• Covers 2007–2010 Yamaha YFM40FB (Big Bear 400) ATVs with 387cc SOHC 4-stroke engine, shaft drive, and wet multi-disc braking system
• Official Yamaha publication P/N 4S11/4S14, first edition consistent with the 2007–2010 model run
• Includes 124 exploded-view component diagrams and 44 critical engine/chassis torque specifications tables
• File link appears in your order confirmation straight away
• Laid out for standard letter and A4 printing
• This OEM edition is the primary source for assembly and service parameters, specifically documenting the wet multi-disc rear brake system not found on earlier variants

Service and Maintenance Documentation

The 2007–2010 Yamaha YFM40FB (Big Bear 400) service manual documents all procedures for what an OEM service publication covers including engine, chassis, and electrical system diagnostics. General sections detail vehicle identification, features, and special tool requirements for engine and chassis maintenance. Periodic check and adjustment chapters outline the maintenance chart for the emission control system, throttle lever free play, valve clearance, and starter cable adjustments. Detailed chapters follow for the carburetor, drive train, chassis components, and electrical system, including circuit diagrams and troubleshooting charts for lighting and starting circuits.

Specifications and Reference Values

This manual contains extensive technical depth regarding engine and chassis specifications to ensure high-performance operation. Cylinder head warpage limits are set at 0.05 mm, while valve clearance for intake is 0.06–0.10 mm in the cold state. Ignition timing for the Big Bear 400 is documented at 10°/1,500 r/min. The torque specifications for 2007–2010 Yamaha Big Bear 400 include engine oil drain bolts tightened to 32 Nm and cylinder head bolts set at 40 Nm in the multi-stage assembly sequence. Fluid capacities are clearly defined, listing the engine oil total amount at 3.5 L and final gear oil at 0.53 L. Standard tire pressure for off-road use is 22–28 kPa. This 388-page Yamaha OEM workshop manual provides technicians and owners with the technical data required to service the YFM40FB engine, chassis, and electrical systems.