Yamaha’s road to big-bore machines began with the creation of the Yamaha Grizzly 600. This large-displacement UTV is a pillar of the ATV landscape and enormously responsible for spawning the 1,000-cc behemoths that are the rave of the off-roading community. This four-wheeler was the centerpiece of the North American outdoor life back in the late ’90s – one of the vehicles that helped restore the ATV industry from near-extinction.
Produced from 1998 to 2001, the Yamaha Grizzly 600 had the largest engine displacement during its time. Boasting a 595-cm3 Paris-Dakar-inspired engine, Ultramatic V-belt transmission, functionality, and pastel bodywork, this 4×4 was a big hit with consumers and off-roaders alike.
Because of its standout features – including individually-controlled front and rear brakes, a one-way sprag clutch, selectable 2WD and 4WD (with a push of a button), oil-cooling system, and towing capacity – it was regarded as the King of 4x4s. Not only did the quad become the talk of the town fast, but it also became a huge contributor to the growth of mud events across the country. Want to know more interesting stuff about the Grizzly 600? Read on.
A Rally-Inspired 4×4
The Yamaha Grizzly 600 4×4, produced from 1998 to 2001, has a 595-cc four-stroke SOHC engine from the big-selling Enduro-style ’86 XT600 Ténéré – a culmination of Yamaha’s efforts to enhance the off-road performance of XT models further and make it more suitable for full-fledged rally competition. The air- and oil-cooled power mill gets its carburetion from a 40-mm constant velocity Mikuni BST. The transmission features a V-belt driven dual-range Ultramatic with reverse, cranked by a primary electric and auxiliary recoil starter with auto decompression. The suspension system uses front MacPherson struts and a mono-cross swingarm for the rear.
It has a total of four trims and at least 11 models throughout its four-year production run, namely:
|1998 Yamaha Grizzly 600||YFM600K|
|1998 Yamaha Grizzly 600||YFM600FWAL|
|1998 Yamaha Grizzly 600||YFM600FWALC|
|1998 Yamaha Grizzly 600||YFM600FWACK (for California)|
|1998 Yamaha Grizzly 600||YFM600FWAK|
|1999 Yamaha Grizzly 600||YFM600L|
|2000 Yamaha Grizzly 600||YFM600L|
|2000 Yamaha Grizzly 600||YFM600FWAN|
|2000 Yamaha Grizzly 600||YFM600FWANC|
|2001 Yamaha Grizzly 600||YFM600FHN (Hunter)|
|2001 Yamaha Grizzly 600||YFM600FN|
Often confused with the Big Bear (before IRS, that is), the Grizzly 600 is a monster on low-end, making it a charm for hauling needs. It rides as well on factory 25-inch tires as on 27-inch 589s, some wheel spacers, and a decent clutch kit. Thanks to its race-ready engine, the wheeler never disappoints – especially when it comes to meeting the whims of off-roaders, young and old. Many riders enjoy this 4×4 in stock form. But aficionados stretch the vehicle’s capabilities further with the aid of a snorkeled belt and motor intake, relocation of the oil cooler, jetting, and lift kits, to name a few.
Cost of a Yamaha Grizzly 600
The current retail price of the quad ranges from $825 to $4,210, depending on the model year, overall vehicle condition, and add-ons. References for the list price of the ’98 model are a bit obscure except for the value of the Hunter Edition. It was the priciest of all the trims released in the market in 2001 for $7,099. For an additional $3,100, consumers can get radio-cassette speakers, high-performance exhaust, power blades, and a snowblower included in the package when buying a brand-new Yamaha Grizzly 600.
Yamaha Grizzly 600 Specs & Features
- Engine: Power comes from a four-stroke, air-/oil-cooled SOHC engine, with a forward-inclined, single-cylinder arrangement and a bore-stroke ratio of 95 x 84 mm (3.74 × 3.31 inches). It has an engine displacement of 595 cm3, a compression ratio of 8.5:1, and a wet-sump lubrication system. 40-mm constant velocity Mikuni BST carburetor and a wet-type air filtration system handle the air-fuel mixture. The vehicle’s horsepower is 37 hp/27.59 kW (short by 3.9 hp compared to the Grizzly 660), top speed is 60 mph stock, and estimated fuel economy is 23 mpg (10.23 liters/100 km).
- Fuel: Fuel tank capacity is 5.1 US gallons/19 liters with a 0.8-US gallon/3-liter reserve. Use unleaded gasoline with an 87+ pump Octane rating or a research Octane number of 91 or higher. To avoid engine damage, only use fuel variants with less than 10% ethanol or 5% methanol.
- Lubrication: Yamaha 600 Grizzly’s oil capacity at disassembly is 2.75 US quarts/2.6 liters, 2 US quarts/1.9 liters without filter replacement, and 2.1 US quarts/2 liters at oil filter change. Use 10W-30, SAE 5W, or 20W-40 Yamalube 4 4-stroke oil or its equivalent for best engine performance. Never mix anti-friction additives in the oil to prevent starter or clutch slippage. Also, make sure not to use oil with Energy Conserving or Energy Conserving II labels. The engine oil should have an API service grade of at least SJ (manufacturer-recommended SE/SF/SG grades are now obsolete).
- Drivetrain: An Ultramatic, V-belt shaft drive and wet, a centrifugal clutch that is left-hand-operated deliver power to the wheels. The one-way sprag clutch maintains constant belt tension for belt wear reduction and increases comfortability and rider confidence, and makes engine braking natural and predictable at all speeds. A three-position On-Command In/Out 4WD feature allows switching between 2WD, limited-slip 4WD, and fully-locked differential 4WD with push-button ease. A 10.2-feet turning radius, mated with a machined Niche Drive clutch Sheave Assembly (view on Amazon), allows for higher gearing and a smoother ride.
- Ignition: The Grizzly 600 uses a CDI ignition with an electric and recoil start system. It has a CDI-magneto generator system that powers up electronic accessories. It also requires a 12V, 18 Ah, 270-CCA (Cold Cranking Amps) YTX20L-BS battery (view on Amazon) with assembled dimensions of 6.88 x 3.44 x 6.12 inches (175 x 87 x 155 millimeters – L x W x H). All trims released in Canada and Europe require an NGKDPR8EA–9 spark plug and an NGKDP8EA–9 for all other models – both of which have a 0.8–0.9 mm (0.03–0.04 inches) gap.
- Tires & Brakes: Tubeless, Dunlop KT404A AT25 × 8-12 front tires and Dunlop KT405G AT25 × 10-12 rear tires mount on 12 x 6.5AT (front)/12 x 7.5AT (rear) aluminum panel wheels. Recommended cold-tire pressure for both front and rear tires is 22-25 kPa (0.22-0.25 kgf/cm2, 3.2-3.6 psi). The maximum recommended pressure is 36 psi/250 kPa (2.5 kgf/cm²) when seating the tire beads. Right-hand operated dual-disc front brakes, and left-hand-and-right-hand-operated rear drum brakes provide the quad dependable stopping power.
- Suspension: The steel tube frame encloses front MacPherson Struts and rear mono-cross swingarm suspension – both with five-way preload-adjustable shocks with 160 mm (6.3 inches) and 190 mm (7.48 inches) of wheel travel, respectively. Coil spring/oil damper type shocks make for maximum control and comfort over rough or bumpy terrain.
- Dimensions: Overall dimensions are 81.4 x 45.7 x 47.8 inches (2,068 x 1,161 x 1,215 mm – L x W x H). The minimum ground clearance is 6.9 inches (175 mm), while the vehicle wheelbase is 49.4 inches (1,254 mm). Its factory-claimed dry weight is 639 lbs/290 Kg (for Europe and Oceania) and 637 lbs/289 Kg for the rest of the market. Curb weight (with oil and a full fuel tank) is estimated at 677 lbs/307 Kg for all versions. The seat height is 34.1 inches – perfect for riders with a 31-inch inseam. A Kimpex 358482 Outback Trunk Rear (view on Amazon) also converts your Grizzly into a two-up vehicle.
- Capacities: The quad’s maximum loading limit is 485 lbs/220 Kg – combined rider weight, cargo, tongue, and accessories. The pulling load limit (total weight of cargo and trailer) is 5,390 N (1,212 lbf/550 kgf). Vertical weight on trailer hitch point is 147 N (33 lbf/15 kgf). The combined rack capacity is 130 Kg – 45 Kg/99 lbs at the front and 85 Kg/187 lbs at the rear. Yamaha Grizzly 600 parts like a WARN 78960 ProVantage Side x Side Straight 60-inch Plow Blade (view on Amazon) lets you maximize the Grizzly’s power output.
- Exterior: The Grizzly 600 comprises a steel tube frame (with a 3° caster angle and 15.5-mm trail) and plastic body material in red, green, and beige. Models released in Europe, Canada, Australia, and some US parts were available in pastel deep green, romantic rouge, deep purplish-blue, and dark grayish-yellow. The Yamaha Grizzly 600 4×4 comes standard with storage compartments and front/rear utility racks. A modest instrument cluster allows riders to keep a tab of mileage and other crucial information. Dual 30-watt Krypton headlights on the front fenders, a 7.5-watt tail/brake light, and 1.7-watt warning indicators provide superior light distribution.
Youtuber Braydon Price talks about a Grizzly 600 he bought off Craigslist. Since it was sitting in the previous owner’s property for over a year, Braydon had to do some mods and replace some parts to get the brute to run. He did give details of the upgrades he did on the quad in this video:
Yamaha Grizzly 600 Problems
Here are the most common challenges owners have encountered with their Grizzly four-wheelers that are worth taking note of:
- Excessive Noise: Perhaps, the most significant setback of having a rally-inspired powerplant is its accompanying noise. To veterans, this is a given and does not bother them at all since the engine top end was based on the old XT600 dual-purpose Enduro bike. Plus, the Grizzly’s considerable power and torque more than compensates for the engine clatter. Fitting the stock exhaust with a silencer cap or getting a Big Gun Exhaust 07-1342 ECO Utility Silver Slip-On Exhaust (view on Amazon) helps reduce noise.
- Overheating: Due to its massive, single-cylinder air-cooled engine, the 2000 Yamaha Grizzly 600 gets hot around the rider’s feet and legs, especially on longer trail rides. The aluminum belt cover and the absence of a water-cooling jacket around the head and cylinder add to this dilemma. The four-wheeler, set up to run lean from the factory, is also a known cause of this issue.
- Starting Problems: Instead of a starter clutch, the Grizzly’s electric starter was based on a jet ski and had a Bendix. This electric and recoil starter setup made it challenging to start the engine. Cranking the engine was accompanied by rattling for a few seconds after the engine has started to run. Yamaha enthusiasts found this comparable to what a Polaris four-wheeler does.
- Sticky Brakes: The drum or brake actuator lever getting stuck is quite common on a Grizzly 600. When this happens, remove the lever from the backplate, clean it with some sandpaper, then re-grease it. Use silicone brake grease to withstand heat better than regular ones and do not swell up the O-ring.
Other anecdotal concerns with the Yamaha Grizzly 600 include the quad being very sensitive to water. Because nothing is between the cylinder and the exterior, the piston reaches around 1000° when in deep water. And once the water cools the cylinder, it shrinks immediately – resulting in engine seizure. Another thing is that the pistons are a bit short on the 600s. During extreme cylinder and piston wear, the piston would kick sideways in the bore and destroy itself. Long before reaching this point, however, the vehicle would have had a loss of compression and quit running.
Yamaha Grizzly 600 Top Speed
The top-end speed of a stock Yamaha Grizzly 700 is 60 mph. Some owners claim to have 62-65 mph stock but advise riders to take a few steps to hit this figure:
- Take the cover off the right-hand side of the engine and take the nut off the shaft.
- Pull the clutch apart and check for flat spots on the wheels. Replace as needed.
- If tire-wheel assembly is in good condition, then clean, regrease, and reassemble.
- If opting for oversized tires, make sure to look into an aftermarket clutch kit. Some recommendations are EPI, Outlaw, or their equivalent.
- Check that the wheels can ride freely throughout the entire range. You may need to tinker with ratios if not.
- Inspect the valve clearance. For the exhaust valves, remove the nut and adjust the gap to .006 to .007 inches. Similarly, set the intake valves to .004 to .005 inches.
- Using a feeler gauge, loosen the lock nut and turn the screw to make adjustments between the valve and the rocker arm. Stock O-rings can usually withstand several adjustments as well.
- Do periodic oil changes, spark plug inspection, and air filter cleanup to restore lost power on pre-loved Grizzlies.
- Check for belt wear (more so when you use your quad heavily for plowing, hunting, and yard duty) and replace it with a new one when worn out.
The above list covers fundamental things you need to do on your four-wheeler, on top of high-performance mods and other servicing needs. Keep in mind that some of these upgrades, while gaining you a few more miles per hour, will take away from your low-end. Veterans also advise owners to take caution when fitting larger knobbies on their 4×4, as they have proven that tires larger than 27 inches can be detrimental to its overall performance. Greasing overkill also does more harm than good on your bike.
Tips for Secondhand Bargains
Here is a video by Outdoor Gorilla covering the obvious and not-so-obvious aspects of a quad that needs checking when buying one secondhand. The presenter demonstrates things to check through a Kodiak, which somewhat shares similar mechanical components with the Grizzly 600:
Other must-check items that were not mentioned or fully explained in the video are as follows:
- Examine if the airbox lid is squeaky clean. If yes, it has been serviced recently.
- The filter down the intake tube should be dirt-free.
- The starter Bendix should stop rattling after a couple of seconds. If it does not, then consider buying a Bendix.
- Pull the plug off the rear differential and stick a pencil or stick down the hole. A brown or rusty color warrants a rear-end rebuild.
- The rear drum brake should not stick. Otherwise, you may need to replace the drum and shoes as a set.
- Loose axle bearings are usually indicative of shot gearcase bearings.
- A soft backfire is commonly associated with a lean idle mixture, a partially plugged pilot jet, an improperly adjusted mixture screw, or an exhaust leak.
- Glowing pipes are almost an expectation, as they are made of stainless steel, which glows red at a much lower temperature than mild carbon steel.
Yamaha Motor Company Limited is among the shapers of the ATV industry and is the maker of the Yamaha Grizzly 600 4×4. This industry-leading company is the world’s best in water vehicle sales and was initially widely known for its piano and reed organ production. Despite being highly respected in the automotive and motorcycle industries, the Japanese conglomerate did not get into these segments until 1945 (after World War II). Parting ways with its parent company in 1955 allowed the firm to focus on developing top-of-the-line product offerings, which include motorsports, off-road vehicles, personal watercraft, speed boats, and outboard motors.
Conclusion – Yamaha Grizzly 600
As the first of its breed, the Grizzly 600 not only paved the way for Yamaha’s big-bore journey but also raised the bar for the competition to follow suit. But while it was recognized as a mighty 4×4 right out of the gate, it had minor hiccups and a flawed suspension that pushed Yamaha to go back to the drawing board.
Its reign as King of 4x4s may have been short-lived, but not in vain. The versions that succeeded it turned out to be revolutionary vehicles that could carry on their predecessor’s legacy. Today, the quad’s lineage continues to offer aid and enjoyment to countless folks and thrill-seekers – thanks to the example set by the Yamaha Grizzly 600 4×4.