Amidst the newfound rave for four-wheeled all-terrain vehicles, Yamaha made a timely move and introduced its first-ever 4×4 vehicle, the Yamaha Big Bear 350. The 350cc machine, launched alongside other pioneer quads, allowed consumers to experience class-leading technology at a reasonable price.
The Yamaha Big Bear 350 was Yamaha’s first 4WD ATV introduced in 1987, along with the Banshee, Warrior, and Terrapro. It featured a front-wheel Torque Control Differential and a dual-range 10-speed transmission with reverse, an electric starter, and a compact frame.
Additional Big Bear variations and model changes increased the four-wheeler’s appeal to consumers. Yamaha’s efforts paid off, as it became a long-time seller along with the other ATV greats.
Even with its reign long gone, many still remember the vehicle for setting the standards for the 4×4 vehicles we have today. Read on and discover more about the Yamaha Big Bear 350.
Start of the Big Bear Series
The Yamaha Big Bear 350 goes down in history as Yamaha’s first 4×4 vehicle. Enthusiasts saw the quad as Yamaha’s reply to the Honda’s FourTrax 350 4×4 – the world’s first 4×4 ATV. It featured a BST34 Mikuni carburetor, a large oil-cooler, a dual-range 10-speed transmission, and Torque Control Differential (TCD).
Produced from 1986 to 1998 (for 1987 to 1999 models), the Big Bear was one of Yamaha’s most successful releases – being in the ATV scenery for 13 consecutive years before giving way to the Yamaha Big Bear 400 4×4 in 2000.
Yamaha Big Bear 350 Models
The Big Bear 350 had three different trims and 13 different model years through the course of its production, namely:
| Year | Model |
|---|---|
| 1987 Yamaha Big Bear 350 4×4 | YFM350FWT |
| 1988 Yamaha Big Bear 350 4×4 | YFM350FWU |
| 1989 Yamaha Big Bear 350 4×4 | YFM350FWW |
| 1990 Yamaha Big Bear 350 4×4 | YFM350FWA |
| 1991 Yamaha Big Bear 350 4×4 | YFM350FWB |
| 1992 Yamaha Big Bear 350 4×4 | YFM350FWD |
| 1993 Yamaha Big Bear 350 4×4 | YFM350FWE |
| 1994 Yamaha Big Bear 350 4×4 | YFM350FWF |
| 1995 Yamaha Big Bear 350 4×4 | YFM350FWG |
| 1996 Yamaha Big Bear 350 4×4 | YFM350FWH (4WD) |
| 1996 Yamaha Big Bear 350 4×4 | YFM350UH (2WD) |
| 1997 Yamaha Big Bear 350 4×4 | YFM350FWJ (4WD) |
| 1997 Yamaha Big Bear 350 4×4 | YFM350J (2WD) |
| 1998 Yamaha Big Bear 350 4×4 | YFM350FK (4WD) |
| 1998 Yamaha Big Bear 350 4×4 | YFM350UK (2WD) |
| 1999 Yamaha Big Bear 350 4×4 | YFM350FHL (4WD, HT) |
| 1999 Yamaha Big Bear 350 4×4 | YFM350FL (4WD) |
| 1999 Yamaha Big Bear 350 4×4 | YFM350UL (2WD) |
Owners love the Big Bear’s suspension and how great it is as a hunting rig. It provides ample storage space for necessities that riders would need to have with them on the trails. It is okay as a full-time 4WD quad, but riders love it more when it came with selectable driveline modes.
The frame, racks, and protective components like the bull bar can be kept in mint condition and last a very long time, given proper care and maintenance. Sticking to scheduled oil changes also keeps the engine in excellent condition.
Cost of a Yamaha Big Bear 350
Depending on model year and trim, the base 4WD model’s price could be anywhere from $2,365 to $4,000. The 2WD version, first introduced in 1996, is within the $3,000 range.
The HT Edition, released only in the Big Bear’s final production year, costs $4,080. Pre-loved wheelers in superb condition could go up to $2,790. Price may be higher if the quad is stock and in mint condition.
Auction listings are between $750 and $9,300, with HT trims holding the highest value. Most of these units are limited to two previous owners and used mainly for yard duty or hunting.
Units valued above $3,000 come with a rebuilt clutch and accessories like a snowplow, gun racks, handguards, and winch. Cheaper ones are in fine working condition but with bad plastics, rusted utility racks, or lights that may need replacement.
Yamaha Big Bear 350 Specs & Features (1997 Model)
Engine
Power comes from a four-stroke, air-cooled, single-cylinder SOHC engine. Its transversely mounted powerplant has a bore-stroke ratio of 83 by 64.5 mm (3.27 × 2.54 inches).
It has an engine displacement of 348 cm3, a compression ratio of 8.6:1, and a wet sump lubrication system.
Top Speed
The top speed of a stock Yamaha Big Bear 350 is 40 mph. Many variables may alter the speed, such as rider weight, terrain, and vehicle condition. In ideal conditions, for example, you may be able to get up to 45 mph.
Fuel Economy
The estimated fuel economy is 20 mpg (11.8 liters/100 km).
The 1996 Yamaha Big Bear 350 has a maximum power output of 17.1 kW (23.2PS) @ 6,500 RPM. 2.64 US gal/10 liters of regular gasoline with a pump Octane number of 87+ and a research Octane number of 91+ is enough to fill the vehicle’s tank.
Lubrication
The Big Bear’s oil capacity at draining is 3.1 US quarts/2.9 liters. At disassembly, it is 3.7 US quarts/3.5 liters. The capacity is 3.2 US quarts/3 liters at an oil filter change.
Depending on ambient temperature, you may use SAE 5W, 10W-30, or 20W-40 Yamalube 4 4-stroke oil or equivalent with an API grade of at least SJ (and no anti-friction modifiers or additives) for best results.
Drivetrain
A five-speed constant-mesh shaft drive and a wet, centrifugal automatic clutch system deliver power to the wheels. It has a primary spur gear with a reduction ratio of 76/24 (3.167).
The first gear ratio is 38/13 (2.923), and the fifth gear is 25/33 (0.758). An 11.1-feet turning radius allows for smoother handling.
Ignition
The Big Bear is brought to life by a DC-CDI ignition with an electric start system and auxiliary mechanical recoil backup. It has an F4T42371/MITSUBISHI AC-magneto generator system powering up electronic accessories.
It requires a 12V, 14 Ah, 190-CCA (Cold Cranking Amps) battery with assembled dimensions of 5.28 x 3.50 x 6.77 inches (134.1 x 88.9 x 171.9 mm – L x W x H), paired with a 30-Amp main fuse.
All U.S.-released models require an NGKD8EA/NIPPONDENSO X24ES-U and an NGKDR8EA for those released in Canada – both with a 0.6–0.7 mm (0.024–0.028 in) gap.
Tires
Tubeless, Dunlop KT404 AT25 × 8-12 front tires and Dunlop KT405B AT25 × 10-12 rear tires mount on panel wheels. 25 kPa (0.25 kgf/cm2, 3.6 psi) is the recommendation for front and rear tires.
Do not go below 3.2 psi/22 kPa (0.22 kgf/cm²) when airing the tires down or beyond 36 psi/250 kPa (2.5 kgf/cm²) when seating the tire beads.
Brakes
A right-hand operated drum brake and a left-hand and right-foot operated drum brake comprise the Yamaha Big Bear 350’s engine braking system.
Suspension
Enclosed in the vehicle’s steel frame is an independent double-wishbone front suspension and swingarm (mono-cross) rear suspension with 98.5 mm (3.88 inches) and 104 mm (4.09 inches) front and rear wheel travel, respectively.
Shocks for both are a coil spring/oil damper type.
Dimensions
Overall dimensions are 76.6 x 43.1 x 45.9 inches (1,945 x 1,095 x 1,165 mm – L x W x H). The minimum ground clearance is 9.65 inches (245 mm), while the vehicle wheelbase is 48.7 inches (1,236 mm).
The curb weight is 259 Kg/571 lbs. The seat height is 32.9 inches.
Capacities
The final gear case oil capacity is 0.26 quarts/0.25 liters and 0.21 US quarts/0.20 liters for differential gear case oil. The four-wheeler’s maximum loading limit is 463 lbs/210 Kg – cargo, trailer hitch/vertical load, rider weight, and accessories).
The horizontal load limit is 904 lbs/410 Kg, while the vertical load is 33 lbs/15 Kg.
Exterior
The Big Bear uses a steel tube frame (with a 2° caster angle and 11-mm trail) and plastic body material. Standard inclusions are hand grips, front and rear fenders with splash guards, footpegs, front and rear bumpers, and utility racks.
Superior light distribution comes from two 25-watt headlights that mount on the front fenders, a 7.5-watt tail/brake light, and 3.4-watt indicator lights. You can convert these to LED lights for improved visibility.
Known Issues
In addition to shifter problems, here are other common problems with the Yamaha Big Bear 350 that you need to be familiar with:
Front Brake Problem
A known issue with the Big Bear 350 is that the front brakes will squeeze right into the bar. If there are no fluid leaks and bleeding the lines on both wheels does not work, then rebuilding the master cylinder is required and should fix the problem for good.
You can source a master cylinder rebuild kit from your dealer – this comes with everything you will need for completing the task.
Giddy Transmission
Sometimes, modifications intended to increase speed can be detrimental to your four-wheeler. Big Bears only go up to 40 mph stock and may manifest transmission problems if forced to go any faster.
Even with proper upgrades, pushing the vehicle to run at higher speeds may result in transmission damage or failure and a blown transmission.
Intermittent Backfiring
Most of the time, this is from a dirty carburetor, a solenoid problem, or wiring issues. In the case of a dirty carb, running some seafoam in your machine does wonders.
If it gets rid of the sputtering, then you may need to thoroughly your carb after. If it is wiring, your owner’s manual will be your best reference.
But in some cases, the fuel you use is to blame. Gas these days are not as compatible with these old machines.
Torque Issues
A dysfunctional spark plug or a cracked or sticky float bowl could cause the quad to lose its torque, even after just a few minutes of riding it.
Do the needful in inspecting the engine and electrical components of the Big Bear. If there is no problem found in these areas, then consult a mechanic for further assistance.
Other Problems
Minor complaints such as insufficient power can be rectified with jetting. It frees up the machine to produce more power and gets rid of uneven idling and popping noises.
You can fix the glowing exhaust by using the right oil.
Putting the Big Bear in Reverse
Several riders have difficulty putting the Big Bear in reverse – either due to a lack of know-how or an actual shifting problem. If you have the same issue, but your vehicle’s brake components check out, then the steps below should enable you to shift into reverse:
- Before shifting, bring the quad to a halt and return the throttle lever to its closed position – this will avoid transmission damage.
- Turn the reverse knob clockwise with your right hand as you apply the rear brake lever.
- Press down on the shift pedal to shift the transmission into reverse.
- Release the rear brake lever.
- Open the throttle lever gradually while ensuring that there are no obstacles or people behind you.
Experienced riders claim it is okay to shift into reverse while in any forward gear, which does not affect the gearing. However, this can be very hard on the clutch, especially if you are in high gear, in mud, or on a steep hill.
About Yamaha
Founded in 1887 in Shizouka, Japan, Yamaha Motor Company Limited began as a piano and reed organ manufacturer. After World War II, Yamaha ventured into the production of motorcycles, later on separating from its parent company in 1955 to become Yamaha Motor Co., Ltd.
Not long after, it spawned the industry of all-terrain vehicles in the ’80s and has not looked back since. Today, the Japanese firm produces off-road vehicles, personal watercraft, speed boats, and outboard motors, including making the Yamaha Big Bear 350 4×4.
Conclusion – Yamaha Big Bear 350 4×4
It may have been lacking even at its launch, but the Yamaha Big Bear 350 4×4 remains an overall capable and well-engineered quad.
For a small machine to hit a top end of 40 mph, haul 900 lbs of weight, last a full day of trail riding, and still perform exceptionally well when needed for work – the vehicle is truly remarkable.
It’s not a speed demon, nor is it a fuel-injected, big-bore behemoth. But it was – and still is – more than adequate, which makes it an excellent four-wheeler for any off-roading enthusiast to own.
Kris is an avid off-roader and outdoor enthusiast who loves to brave the elements and take on challenging terrain. He also enjoys sharing his passion and knowledge with others so that they, too, can appreciate the ride.
About Kris