Yamaha Grizzly 660 Specs and Review

ATV Quad Race Competition

The recent millennia saw the rise of V-belt transmission, four-stroke, fuel injection, and the Yamaha Grizzly 660. Following closely behind the Raptor, this almost-big-bore machine addressed its precursor’s shortcomings when it entered the ATV scene in 2002. It had a sporty look, a powerful engine, and a utilitarian build that promised tons of fun on the ranch as it did on the trails.

The Yamaha Grizzly 660 was a spin-off of the Raptor 660, produced from 2001 to 2006. Fondly called the Bear or Grizzly, this four-wheeler boasted a sportier look, an Ultramatic transmission, and an improved suspension. These standout features made the quad a top choice for trail riding and chores.

Execution is everything, and Yamaha did right in this aspect with the Yamaha Grizzly 660. Along with its toughest competitors such as the Ranger, Sportsman, and Rincon, the machine unfalteringly delivered the ultimate riding adventure to both trail and aggressive riders. It may be considered dated or puny by today’s standards, but when it came out, it was an unrivaled 4×4. Continue reading, and relive the glory days of the Grizzly.

The Mega ATV, Overhauled

The Yamaha Raptor 660, considered The Ultimate Sport Quad, earned such a stellar reputation that Yamaha deemed it best to create another model that derived its engine from this iconic vehicle. Hence, the 2002 Yamaha Grizzly 660 was born. Unlike its predecessor, the Grizzly did not have dual carburetors. But it did utilize a robust 44-mm Keihin carburetor and five-valve cylinder head, independent double-wishbone suspension, and hydraulic disc brakes – instantly making it one of the go-to four-wheelers in its category.

Produced from 2001 to 2006 (for 2002 to 2007 models), this rec-utility vehicle stayed in the market for six consecutive years. It launched with a newly construed chassis, designed to address the biggest shortcoming of its stablemate, the Raptor. Double-A-arm, independent suspension on all fours with sway bars replaced the former front MacPherson better struts and rear swingarm suspension. It also had a push-button front differential lock and improved instrumentation.

Yamaha Grizzly 660 Models

The Grizzly had several different trims through the course of its production, namely:

YearModel
2002 Yamaha Grizzly 660YFM660FPE
2002 Yamaha Grizzly 660YFM660FHP Hunter
2003 Yamaha Grizzly 660YFM660FR
2004 Yamaha Grizzly 660YFM660FS
2005 Yamaha Grizzly 660YFM66FAHT (4WD, Camouflage)
2005 Yamaha Grizzly 660YFM66FASET Special Edition (4WD)
2005 Yamaha Grizzly 660YFM660FAT (4WD)
2006 Yamaha Grizzly 660YFM66FABGHV Outdoorsman Edition (4WD, Camouflage)
2006 Yamaha Grizzly 660YFM66FAHDV Ducks Unlimited Edition
2006 Yamaha Grizzly 660YFM66FAHV (4WD, Camouflage)
2006 Yamaha Grizzly 660YFM66FASEV Special Edition (4WD)
2006 Yamaha Grizzly 660YFM66FAV (4WD)
2007 Yamaha Grizzly 660YFM66FGHW (Camouflage)
2007 Yamaha Grizzly 660YFM66FGW

Yamaha fed the Grizzly 660 so well that it remained among the quads with top popularity and sales, despite the emergence of multi-cylinder beasts from the competition. It was not until the advancing tide of technology in 2007 that Yamaha had to update the Grizzly to include a 32-bit ECU for power steering, a 44-mm throttle body for fuel injection, and a larger displacement of 700 cm3. Additionally, cost-effectiveness and the aim for weight savings resulted in the Grizzly shifting to a four-valve cylinder head and a redesigned frame and suspension and losing its auxiliary mechanical pull-starter.

Blue 2008 Yamaha Grizzly 660 ATV

Yamaha Grizzly 660 Price

The original list price in 2002 for the base model was $6,999 and $7,299 for the Hunter Edition. The base model cost only increased to $7,199 on its last production year. There were minimal increases for the Hunter Edition trims, $7,949 (2006 Outdoorsman Edition) and $7,699 (2006 Ducks Unlimited Edition). The 2006 Special Edition cost $7,599, which came with a sleeker finish and was only $50 more than the 2007 Camouflage trim.

Kelley Blue Book values are between $2,275 and $4,000, with 2006 models holding the highest value due to the number of trims released that year. Trade-in values are from $1,990 to $2,700 for units in good condition and with typical mileage. Mods and additional accessories may add to the vehicle’s worth. On the other hand, secondhand Grizzlies range from $1,700 to $2,100 but tend to be scarce on trader and auction sites. Some units open for bidding come with free shipping. Be wary of quads selling for less than $1,500, as they may come with non-working shafts, a weak battery, or deteriorated plastics.

Yamaha Grizzly 660 Specs

  • Engine: It uses a four-stroke, liquid-cooled, single-cylinder SOHC engine. The forward-inclined powerplant has a bore-stroke ratio of 100 by 84 mm (3.94 × 3.31 inches). It has an engine displacement of 660 cm3, a compression ratio of 9.1:1, and a wet sump lubrication system. A 42-mm Mikuni BSR42/1 carburetor and a wet-type air filtration system handle the air-fuel mixture. The vehicle’s horsepower is 40.9 hp (as of 2010), top speed is 70 mph stock, and estimated fuel economy is 14 mpg (16.8 liters/100 km).
  • Recommended fuel: Use unleaded gasoline with a pump Octane number of 86+ and a research Octane number of 91 or higher. To avoid engine damage, make sure to use a fuel variant with less than 10% ethanol and less than 5% methanol.
  • Lubrication: Yamaha Grizzly 660’s oil capacity differs with and without an oil filter change. At draining, it is 2 US quarts/1.9 liters. At disassembly, it is 2.2 US quarts/2.3 liters, and the oil filter change capacity is 2.1 US quarts/2 liters. Use SAE 5W, 10W-30, or 20W-40 Yamalube 4 4-stroke oil or equivalent motor oil for top performance. Ensure that it also has an API service classification of at least SJ (manufacturer-recommended API grade of SE/SF/SG are already obsolete) with no anti-friction modifiers.
  •  Drivetrain: An Ultramatic, V-belt shaft drive and wet, centrifugal clutch system (L/H/N/R/P) are left-hand-operated deliver power to the wheels. The low sub-transmission ratio is 37/15 (2.466), and the high is 28/19 (1.473). A 10.5-feet turning radius allows for a smoother ride.
  • Ignition: It uses a DC-CDI ignition with an electric start system and auxiliary mechanical recoil backup. It has an F4T496/MITSUBISHI AC-magneto generator system powering up electronic accessories. It requires a 12V, 18 Ah, 270-CCA (Cold Cranking Amps) battery with assembled dimensions of 6.88 x 3.44 x 6.12 inches and a 10-Amp fuse.
  • Tires: Tubeless, Dunlop KT131 AT25 × 8-12 front tires and Dunlop KT135 AT25 × 10-12 rear tires mount on steel rims. Recommended tire pressure for front tires is 32-38 kPa (0.32-0.38 kgf/cm2, 5.5 psi) and rear tires is 27-33 kPa (0.27-0.33 kgf/cm2, 4.8 psi). Do not go beyond 3.9 psi/27kPa (0.27 kgf/cm²) and 36 psi/250 kPa (2.5 kgf/cm²) when seating the tire beads.
  • Brakes: Right-hand operated dual disc brakes, and a left-hand and right-foot operated single-disc rear brake provide the Yamaha Grizzly 660 its stopping power.
  • Suspension: A steel tube frame encloses an independent double-wishbone front and rear suspension with preload adjustment and 170 mm (6.69 in) and 225 mm (8.86 in) of wheel travel, respectively. Shocks for both are a coil spring/oil damper type.
  • Dimensions: Overall dimensions are 82.1 x 45.3 x 47.6 inches (2,085 x 1,150 x 1,210 millimeters – L x W x H). The minimum ground clearance is 10.8 inches (275 mm), while the vehicle wheelbase is 50.2 inches (1,275 mm). The curb weight is 290 Kg/639 lbs – heavier than the Yamaha Raptor 660. The seat height is 34.6 inches. The 2004 Yamaha Grizzly 660 has a dry weight of 272 Kg/600 lbs.
  • Capacities: Its fuel capacity is 5.3 US gallons/20 liters with a 0.92-US gallons/3.5-liter reserve. Radiator capacity is 1.90 quarts/1.8 liters. The final gear case oil capacity is 0.32 quarts/0.30 liters and 0.35 US quarts/0.33 liters for differential gear case oil. The quad’s maximum loading limit is 485 lbs/220 Kg – cargo, rider, and accessories).
  • Exterior: It has a steel tube frame (with a 5° caster angle and 26-mm trail) and plastic body material. The four-wheeler comes standard with hand grips, front and rear fenders, footrests, and front and rear bumpers. Dual 30-watt headlights mounted on the front fenders, a 5-watt taillight, and a 21-watt brake light provide superior light distribution. The rest of the warning indicators found on the center console are LED lights.

In this video, ATVTV rates a 2005 Yamaha Grizzly 660 after a quick test of the vehicle:

How Fast Is a Yamaha Grizzly 660?

The top speed of a stock Yamaha Grizzly 660 is 70 mph. This figure may change, depending on altitude, temperature, humidity, rider weight, terrain, modifications, and overall vehicle condition.

Pros and Cons

It’s important to examine the pros and cons of a four-wheeler before making a purchase decision. Here are a few things to consider:

Pros

  • Its single carburetor delivers tons of power and gives excellent performance on hard-packed roads.
  • It has one of the best 4WD locker switches in an ATV.
  • Radial tires dramatically enhance handling.
  • The overall built of the machine makes it a top choice for leisurely rides or serious hauling.
  • Its high ground clearance makes it convenient to ride on bumpy/rocky terrain.
  • This machine is ideal for all-day riding due to its plush suspension and handling.
  • Riders agree that it has the best belt system in its class.
  • Snorkels are mounted higher than most ATVs, making them perfect in deep water.
  • The power-to-weight ratio is decent and makes the Grizzly a reliable machine.
  • It has more massive aftermarket support compared to its counterparts.
  • Large racks and higher towing capacity make it a sounder utility vehicle.

Cons

  • Difficulty in finding reverse and IRS squat dampens the Yamaha Grizzly 660’s strength as a chore vehicle.
  • The park position can be accidentally engaged while trying to shift from the reverse.
  • Off-cambers and uneven obstacles are not part of its forte.
  • The rear axle seems to always pop out from the rear differential.
  • Leaving it in the garage for a while results in the machine not getting any fuel.
  • Its fuel mileage and consumption are among the worst in its class (only corrected with the 2014 model onwards).
  • Cylinders on the Grizzly are not Nikasil-coated (which may mean extra expense for mud boggers).
  • Aesthetics is not the most handsome or most appealing out in the market.
  • It is not advisable for young riders as they may not handle the machine’s weight and power.

Other Drawbacks

In addition to the above setbacks, here are a few more known issues with the Grizzly worth noting:

  • Bad front driveshaft: Elongating the differential mount holes on the frame and moving the diff ¼” closer to the engine can remedy this problem.
  • Excessive oil burning: This problem links to 2002-2004 models. Several factors may lead to the vehicle burning oil excessively – doing compression and leak down test will help point you towards the right place to look. Accompanying symptoms also help. For instance, smoke during cold starts may be indicative of worn rings or valve stem seals. The absence of smoke usually specifies an oil leak.
  • Moving rear differential: It is known to move or twist in the frame. Therefore, inspecting this part of the Grizzly is a must, especially for older models. Checking for bent or broken mounts is also recommended.
  • Overheating: Symptoms usually include a burnt-oil smell, white smoke, and restrictive startup. Causes could either be a blown gasket or exhaust valve guides and seals (if left unused for a long time, as in the case of snowplow Grizzlies).

Most of these drawbacks are self-inflicted, if not circumstantial. Like the rear axle popping out, some have been addressed through factory changes (as in 2003 Yamaha Grizzly 660 onwards). Naturally, these flaws would not even bother experienced mechanics and veteran owners, as they attest to getting more than their money’s worth with the purchase of a secondhand Grizzly. But for enthusiasts who want more, they have to bear in mind that upkeep and a few appropriate mods are needed to draw the most out of this behemoth.

Red 2002 Yamaha Grizzly 660 Quad

How to Make the Yamaha Grizzly 660 Faster

Often, the reason behind the endless attempts at customizing the Grizzly is the rider’s need for speed. Over the years, professional mechanics and savants have equipped these machines with all kinds of Yamaha Grizzly 660 parts to increase the four-wheeler’s top end. Below are some of the suggested upgrades that can improve your quad’s speed:

  • 27″ Vampires on C-Series type 4
  • 26″ 589s and 29.5″ Outlaws, or Kenda K587 Bear Claws (view on Amazon) as an alternative
  • 1.5-inch wheel spacers front, 1-inch wheel spacers rear
  • Pro Flow K&N filter
  • HMF full pipe
  • Slip-on exhaust
  • EPI clutch
  • Full aluminum skids
  • PROCOM CDI & Rectifier
  • Works Performance AT-Steeler shocks
  • Dyno Q415 Jet Kit (view on Amazon)
  • Machined clutch sheave
  • 14-gram greaseless weights
  • 2-mm shim

About Yamaha

Yamaha Motor Company Limited, the world’s best in water vehicle sales, is the maker of the Yamaha Grizzly 660. This Japanese firm started as a piano and reed organ manufacturer in 1887. It was not until after World War II that the company ventured into the production of motorcycles. Eventually, it separated from its parent company in 1955 to become Yamaha Motor Co., Ltd and built the ATV industry two and a half decades later. Today, the product offerings of this industry leader span from motorsports, off-road vehicles, personal watercraft, and speed boats to outboard motors.

Conclusion – Yamaha Grizzly 660

The Yamaha Grizzly 660 can conveniently get lost in the superlatives of its competitors such as the Prairie, Rincon, and Vinson. Despite this, it is still a capable machine that has remained at the forefront of the ATV scene. Maneuvering the vehicle boosts confidence and almost feels like riding an extension of yourself.

The faint-hearted may find the Grizzly’s proclivity for unloading its suspension mid-corner a tad nerve-wracking, especially when negotiating a switchback. But its responsive engine, braking system, and CVT transmission never fail. It has given many riders joyous moments and challenging situations, and it will continue to do so for the years to come.

Kris Peter

Adventure seeker and off-road enthusiast. I love the thrill of going off-road and taking on the elements.

Recent Posts