2012 Yamaha Big Bear 400 4x4 IRS

The name of this Yamaha ATV is the Big Bear 400 and it’s as imposing as its name suggests, and it also provides a lot of useful features for hard core ATV riders.

Aesthetically, the ATV has flat-style handlebars that help provide light steering effort and great rider comfort while the large front and rear fenders offer excellent mud and splash protection. The ATV also has a water-resistant, large-capacity underseat storage box; a specially designed, thickly padded seat for rider comfort; rugged, serrated footrests that have excellent grip; and a huge set of 25" ITP Mud Lite tires.

Growling inside the Big Bear 400’s special compact frame design is a simple yet powerful 386cc air and oil-cooled, SOHC engine that breathes through a heated, semi-oval slide 33 mm BSR Mikuni carburetor, providing seamless throttle response and excellent all-weather performance. The engine is mated to a constant-mesh five-speed transmission that comes with an automatic clutch, a reverse gear, and a super-low stump-pulling first gear. Complimenting the ATV’s sturdy steel frame is an independent rear suspension that offers maximum ground clearance, excellent terrainability, and all-day comfort riders require for their vehicle. The ATV also has a sealed wet brake out back to provide impressive stopping power even in tough conditions.

One prominent feature of the Big Bear 400 is its class-exclusive, three-position On-Command In/Out 4WD feature which lets you switch between different sorts of drive systems, including 2WD, limited-slip 4WD, and fully locked differential 4WD, all by just a simple push of a button.

Find out more about the Yamaha Big Bear 400 after the jump.


Yamaha Big Bear 400 4x4 IRS
  • Simple yet powerful 386cc air/oil-cooled, SOHC engine inhales through a heated, semi-oval slide 33mm BSR Mikuni carburetor for seamless throttle response and excellent all-weather performance.
  • DC-CDI ignition system ensures dependable starting and puts out consistent spark at all rpm for optimal engine performance.
  • Large-capacity oil cooler with cooling fan helps maximize engine efficiency, even under heavy loads.
  • Stainless steel muffler and header provide superior power characteristics, exhaust sound and unmatched durability.
  • Tool-free, easy-access air filter box.
  • Automatic cam chain tensioner reduces engine maintenance and helps extend engine life.

Chassis and Suspension

Yamaha Big Bear 400 4x4 IRS
  • Special compact frame design uses fewer components to reduce weight and provide lighter steering, a tighter turning radius, and superior durability.
  • Class-leading turning radius provides maximum maneuverability on tight trails and while working with heavy equipment.
  • Independent double-wishbone front suspension with five-way preload-adjustable shocks and 5.8 inches of travel.
  • Independent rear suspension with five-way preload adjustment and 7.6 inches of travel provides excellent handling and all day comfort.
  • On-Command drive selection with Diff. Lock lets you access full power from 4WD locked.
  • Low seat height for great handling.
  • Plenty of ground clearance and a high mount air intake makes this machine ready for muddy conditions.
  • Large-diameter ventilated hydraulic front disc brakes and a sealed rear wet brake provide plenty of stopping power in a variety of conditions.
  • Reliable, low-maintenance front and rear shaft drive.
  • Specially designed A-arms with removable ball joints provide smooth operation and outstanding reliability.
  • Built-in winch mounts.

Additional Features

Yamaha Big Bear 400 4x4 IRS
  • -*Wrinkle-finish cargo racks are super-durable and can pack a class-leading total of 264 pounds (88 front, 176 rear) of payload.
  • Speedometer with odometer/tripmeter adds greater versatility and allows rider to keep track of engine maintenance intervals.
  • Standard center-mounted trailer hitch can hook up more than 1100 pounds of payload.
  • Full floorboards, lots of ground clearance, and a high-mount air intake are ready for mud.
  • Flat-style handlebars help provide light steering effort and great rider comfort.
  • Large front and rear fenders with inner splash guards offer excellent mud and splash protection.
  • Water-resistant, large-capacity underseat storage box provides added convenience.
  • Heavy-duty, full-coverage A-arm and CV joint boot protectors help prevent damage to boot covers.
  • Specially designed, thickly padded seat is widely contoured for incomparable rider comfort.
  • Large-capacity, 4-gallon fuel tank has a built-in gauge. Mud and water-resistant automotive-type DC power outlet powers a wide range of accessories.
  • Rugged, serrated footrests provide excellent grip and rider comfort with superb durability.
  • Maintenance-free 18-amp-hour battery provides extra starting power.
  • Underseat marine-spec electrical components ensure maximum protection from the elements and easy access.
  • Bright multireflector 30-watt headlights feature wide positioning to maximize low-light and nighttime visibility.
  • Easy-to-use, handlebar-mounted parking brake and choke lever.
  • Assembled in Newnan, GA, U.S.A.


Yamaha Big Bear 400 4x4 IRS
Engine Type386cc, 4-stroke, air/oil-cooled single; SOHC
Bore x Stroke83.0 x 71.5mm
Compression Ratio8.6:1
Fuel DeliveryMikuni 33mm BSR
Starting SystemElectric w/auxiliary pull
Transmission5-speed w/reverse; automatic clutch;
front- and rear-wheel engine braking
Drive TrainYamaha On-Command pushbutton;
3-way locking differential; 2WD,
4WD, locked 4WD; shaft drive
Suspension/FrontIndependent double wishbone;
5-way preload adjustment, 5.8-in travel
Suspension/RearIndependent double wishbone;
5-way preload adjustment, 7.6-in travel
Brakes/FrontDual hydraulic disc
Brake/RearSealed oil bathed, multi disc
Tire/FrontAT25 x 8-12 ITP Mud Lite
Tire/RearAT25 x 10-12 ITP Mud Lite
L x W x H79.4 x 43.9 x 46.7 in
Seat Height35.2 in
Wheelbase48.4 in
Turning Radius126 in
Ground Clearance10.5 in
Fuel Capacity4.0 gal
Wet Weight628 lb
Rack Capacity88 lb Fr./176 lb Rr.
Towing Capacity1102 lb
InstrumentationSpeedometer, odometer, fuel gauge
LightingDual 30W Krypton multireflector
headlights & 21W/5W brakelight
ColorSteel Blue; Hunter Green;
Realtree AP Camouflage

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