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Suzuki Quadzilla 500 Specs & Review (QuadRacer LT500R)

Earning a nickname coined from Gojira or Godzilla, the Suzuki Quadzilla 500 is every bit as powerful and formidable as Japan’s “King of Monsters.” Since its inception, this iconic sport quad had every rider and avid enthusiast awe-stricken. Its seemingly turbocharged powerband and unrivaled agility enthralled the riding community to a great extent – an effect in many ways similar to the 1954 fictional creature that terrorized the whole of Tokyo and left the city in ruins.

The Suzuki Quadzilla 500 (a.k.a. Suzuki QuadRacer LT500R) is considered the fastest production ATV ever made and one of the most powerful in existence. Produced from 1987 to 1990, this sport quad featured a 51-hp power output and a 499-cm3 piston displacement – a first for 2-strokes in the market.

Despite its short-lived run, the Suzuki 500 Quadzilla continues to be celebrated as one of the greatest racing machines of all time. Read on and learn more about the ATV that inspired modern-day performance quads, as well as the specs, highs and lows, and praiseworthy features that put the Quadzilla in the same ranks as Japan’s fire-breathing monster.

Blue and Yellow ATV Quad Runner

The Tale of the Beast – Quadzilla 500

The Quadzilla 500 is, perhaps, one of the most interesting sport quads to have ever been produced by any ATV manufacturer. It is not because of its sheer size nor fire-breathing nature, but rather its famous moniker. For most ATVs in the market, it is the manufacturer that assigns them a nickname – largely for easier consumer recall and marketing. However, this was not the case with the LT500R.

Although released as the Suzuki QuadRacer LT500R in 1987, the four-wheeler became more popularly known as Quadzilla – an allusion to Japan’s Godzilla. Like the massive size and capabilities of this 1950’s silver-screen monster, the Quadzilla was gigantic, powerful, and quick to devour any quad on the racetracks. Notwithstanding flaws in its suspension geometry and overall design, it made perfect sense to give the machine a name befitting what it had to offer.

In addition to its humungous size and speed, the LT500 Quadzilla is famous for its notoriety. And while there is no such thing as too much in the world of sport riding, some riders deemed the LT500R too strong and too dangerous. In truth, riders’ disrespect for the quad’s power and disregard for rider safety gave the machine an unfortunate reputation, arguably leading to its past demise and current collectible value.

Suzuki Quadzilla 500 Specs & Features


The Suzuki LT500R is powered by a liquid-cooled, 2-stroke SAEC power mill. It has a bore x stroke ratio of 86 x 86 mm (3.386 x 3.386 inches). Piston displacement is 499-cm3 (30.4 in3), while the corrected compression ratio is 6.3:1. A flat-slide Mikuni TM38SS carburetor handles air-fuel mixture, supplemented by polyurethane-foam-element air filtration.

Suzuki Automatic Exhaust Control (SAEC) power valve amplifies the LT500R’s powerband across all RPMs, lending to a Dyno-tested Quadzilla 500 top speed of 82 mph (132 km/h) and a horsepower of 51 RWHP (37.5 kW). Some owners report their machines having 70 hp, 62.37 Nm (6.36 kgf-m, 46 ft-lb) maximum torque, and well over 100 mph (161 km/h) with appropriate mods and correct gearing.

Quadzilla Changes

It is worth noting that the engine configuration for the 1987 Suzuki LT500RH differs from that of later-year models. Below are changes made to the Quadzilla, beginning with the 1988 LT500RJ:

  • A wear-resistant molybdenum overlay has been applied to the inside surface of the piston. Additionally, the latter’s circlip groove diameter has been slightly reduced from 19.9 mm to 19.5 mm, and its length increased by 1 mm.
  • The oil seal balancer shaft size/I.D. increased from 23.6 mm to 30.8 mm. Similarly, Suzuki altered the shape of the crank balancer.
  • The cylinder head cover has been changed and is not interchangeable between the ’87 and ’88 models.
  • 1987 LT500Rs had eight (8) reed valves, while succeeding-year models had six (6).
  • Stamped markings on the exhaust valve retainer changed from 250 to 500.
  • The mounting method for the polyurethane foam element changed from screw-type to clip type.
  • Main, pilot, and starter jetting were different between the first and remaining models of the Suzuki LT500.

Fuel & Lubrication

Fuel tank capacity is 13 liters (3.4 US gallons, inclusive of a 1.3-liter/0.34-US gallon reserve) of low-lead type gasoline with a minimum PON 85-95/RON 89+ rating, containing < 5% MTBE (Methyl Tertiary Butyl Ether), < 10% ethanol, or < 5% methanol and with appropriate cosolvents and corrosion inhibitors.

Lubrication-wise, the sport quad has a 20:1 fuel-oil premixture that requires SAE 20W-40 of Suzuki CCI/CCI Super 2-Cycle engine oil type or its equivalent. Oil capacity is either 1.0 liters (1.06 US quarts – change) or 1.1 liters (1.16 US quarts – overhaul). For best results, use motor oils with a minimum API grade of SJ+ meeting JASO T903 MA standards.


A 5-speed constant-mesh transmission and a wet, multi-plate centrifugal clutch assembly (with a 1-down 4-up shift sequence) deliver power to the wheels for the LT500R. A Takasago RK520 SMOZ10S O-ring sealed chain (96 links + joint) handles wheelspin and can be replaced with an RK GB520XSO-120 Racing Chain (view on Amazon) in case of wear or damage.

A gear-driven counter-balancer reduces engine vibration and lends to the machine’s superb and predictable handling – whether on wooded trails or technical tracks.

For reference, the stock gear ratios are below:

Primary Reduction Ratio2.142 (60/28)
Final Reduction Ratio3.076 (40/13)
Transmission Gear Ratio (Low)2.416 (29/12)
Transmission Gear Ratio (2nd)1.733 (26/15)
Transmission Gear Ratio (3rd)1.333 (24/18)
Transmission Gear Ratio (4th)1.100 (22/20)
Transmission Gear Ratio (Top)0.909 (20/22)


It is brought to life by a primary kick-start system and Suzuki “PEI” CDI with a timing of 4° ± 1.5° BTDC @ 1,000 RPM – 15° ± 0.5° BTDC @ 5,500 RPM. It also has a flywheel magneto with a power output of 13-14V @ 5,000 RPM that acts as its charging system. Furthermore, it requires an NGK B8EGV spark plug with a 0.55–0.65 mm (0.022–0.026 inch) gap and a 12V, 12Ah/(10 HR) YTX14AH-BS battery (view on Amazon) with assembled dimensions of 134 x 89 x 166 mm (5.31 x 3.50 x 6.56 inches).

Note: Canada releases require an NGK BR8EV (0.5–0.6 mm, 0.020–0.024 inch gap) spark plug.

Tires & Brakes

Stock rubber consists of AT21 x 7-10 front and AT20 x 11-10 rear tires with respective 4/166 mm and 5/130 mm bolt patterns. These fully corded tires mount on aluminum rims. Triple hydraulic discs (view on Amazon), each with a single-piston-caliper design, complete the Quadzilla’s tire-and-wheel assembly.

Recommended cold-tire pressure for front tires is 30 kPa (0.30 kgf/cm2, 4.4 psi) and 25 kPa (0.25 kgf/cm2, 3.6 psi) for the rear. You can increase tire pressure to 35 kPa (0.35 kgf/cm2, 5.1 psi) if load capacity reaches between 80-120 Kg (175-265 lbs.). Never go beyond the range of 45 kPa (0.45 kgf/cm2, 6.5 psi) when inflating tires or to 250 kPa (2.50 kgf/cm2, 36 psi) when seating tire beads.


The front suspension consists of dual A-arms with adjustable spring preload and 4-way rebound damping. The rear has a progressive-rate/Full Floater linkage (box-type aluminum swingarm and remote gas-charged damper) with adjustable preload, 21-way compression, and 26-way rebound damping. Each setup provides 9.1 inches/231 mm of wheel travel (already considered plenty at the time), which others may find inadequate compared to present-day trail quads.

The steering angle is 32° (inside) and 25° (outside), and the toe-in is 11-19 mm (0.4-0.7 inch). Minimum ground clearance is 110 mm (4.3 inches) at the rear axle, while the wheelbase is 1,345 mm (53 inches). The turning radius is 2.8 meters/9.2 feet and, although slightly inferior to Suzuki’s very own Vinson 500, makes for ease of maneuverability in technical trails and cornering angles.

The Suzuki 500 Quadzilla did receive some chassis refinements during its 4-year production. However, most of these upgrades were cosmetic (changing the color of the A-arms), if not due to manufacturing cost-effectiveness. The rebuildable rear Showa damper was made according to Suzuki’s specifications (after the RM line of MX bikes in the ’80s) but afforded no upgrade to the quad’s limited ground clearance. Thankfully, getting taller tires and an appropriate lift kit can improve the latter and make room for an aftermarket skid plate.


Overall dimensions are 75.6 x 47.4 x 43.7 inches (1,920 x 1,205 x 1,110 mm – L x W x H). Seat height is a decent 790 mm/31.1 inches, and front/rear track is 1,030 mm (40.6 inches)/900 mm (35.4 inches). Dry weight is 178 Kg (392 lbs.), while GVWR (Gross Vehicle Weight Rating) is estimated at 311 Kg (686 lbs.) – inclusive of a full tank, rider weight, cargo, and accessories.

Note: Despite chassis enhancements, the quad’s length, width, and height remained unchanged throughout its production run.


The Suzuki LT500R is a huge machine, even slightly larger than the Vinson 500. On the outside, it looks like a bigger version of the 1985 LT250R hailing from the same QuadRacer family. Both share similar sport-oriented designs available in yellow and blue color schemes. The only difference is in the positioning of the vane on the radiator grille of each machine.

As for distinctions between LT500R versions, earlier models had silver-colored dual A-arms, later changing to white for 1989-1990 versions. The ’87 LT500RH particularly had bulky A-arms made with square tubing, while the ’88 LT500RJ A-arms received circular tubing, was slightly longer, and 45% lighter than the former. The graphics differed for each year. And except for the ’87 LT500RH, all other models had the rear crossbar reinforced as it was prone to bend.

Other than the above, the Suzuki Quadzilla 500 received very few enhancements during its lifetime. On a brighter note, a wide front bumper, fiberglass skid plate, and aerodynamic fenders already come with the vehicle. These standard inclusions not only protect the quad’s underside and side panels from scuffs but also add to its overall racing-oriented design.

Worth of a Suzuki LT 500

The list price of the Quadzilla 500 started at $3,299, increasing by only $1,000 for its final production model (or in increments of $300-$400 each year). It would be worth approximately between $7,900 and $10,350 today. Since it was a class of its own at the time, there is no value comparison with its counterparts.

Year – Trim – Model #List PriceRetail/Trade-In Values
1987 Suzuki LT500RH QuadRacer$3,299$255 – $1,935
1988 Suzuki LT500RJ QuadRacer$3,599$300 – $2,045
1989 Suzuki LT500RK QuadRacer$3,999$300 – $2,140
1990 Suzuki LT500RL QuadRacer$4,299$325 – $2,250

Auction listings on Craigslist, eBay, and other trader sites show a resale value between $3,600 to $4,000. Most of these machines are ’87 and ’88 models. You will rarely find ’89 and ’90 Quadzillas for sale, as these units were at the receiving end of most of the upgrades Suzuki gave the quad – making it difficult for enthusiasts to let go.

But there are a few listings below $1,000. Make it a point to visually inspect these units before buying, as they are mostly either in terrible condition or sold for parts.

A secondhand unit in good working condition would normally warrant only a few things – new Stage-4/5 Elka shocks (view on Amazon), polished aluminum, and paddle tires for the dunes. The most expensive mod it would probably need is a full motor rebuild, complete with cylinder porting, billet exhaust clamp, new silencer, clamp-on air filter, and a bigger carburetor costing approximately $6,000 in total.

If you only need to reinforce the rear, professional outfitters like Duncan Racing can fabricate a chrome-plated +2 Laeger swingarm for the 500-cc Quadzilla for approximately $1,000.

Quadzilla – The Good and Bad

The Quadzilla 500 was such a beast in power and performance that it got more than a few riders overwhelmed. Fearlessness turned into negligence for some of these folks, which consequently got themselves hurt. Eventually, these anecdotal incidents led to the four-wheeler developing a bad wrap, pushing Suzuki to cease the production of the LT500R after only four years.

So much more could have taken place to improve the quad’s competencies if given more time. It would have been insanely cool if the Quadzilla were still mass-produced today and given technology like IRS and fuel injection. But here we are in the present, stuck with a rare, three-decade-old breed. And we can only hope that its former owners gave it great care, lest we deal with a quad in need of tons of help.

Quadzilla 500 Problems

The LT500R’s problems involve its stock breathing and jetting – a downside of having unrefined power valves (variable exhaust ports). Some enthusiasts and test riders wish for a tighter gap between 2nd/3rd gears and 3rd/4th to reduce inconsistencies in the powerband and transmission. Inexperienced riders may also find themselves committing missed shifts due to the quad’s old-school shift system and clutch assembly.

Luckily, an aftermarket engine kit can modify the stock motor positively. Obtaining stock gear parts or swapping the placement of 2nd/3rd or 3rd/4th gears (a DIY fix by some mechanics) also helps achieve a closer gear ratio. There are loads of helpful information online and in dedicated forums that provide the best tricks on how to fine-tune or resurrect the LT500R to near-perfection.

Requires Skill and Experience

Jumpsters will be happy to know it does not require heavy revving to get the Quadzilla a considerable height off the ground. However, not just anyone can have the privilege of this experience. Unlike 250-cc sport quads that are friendly to beginners and more advanced riders, the Suzuki LT500R is not as forgiving. Riding this beast requires a certain level of skill and experience, not to mention a strong grip to keep the machine (and your spirit) from running away from you.

About Suzuki

Suzuki Motor Corporation is one of the Big 4 Japanese forces to be reckoned with in the automotive and motorsports industries. Founded in Hamamatsu in 1909, the Japanese firm ironically started as a weaving loom business, only diversifying its product offerings after 28 years. Suzuki ventured into small-car manufacturing in 1937 and eventually into ATV production in the ’80s, leading to the Suzuki Quadzilla 500.

Since then, Suzuki has successfully pioneered industry-leading concepts and machines and continues to do so today. And it is this continuous aim for excellence that made the firm a powerhouse in the automotive industry and one of the most successful automakers by production worldwide. At present, Suzuki has over 133 distributors in 192 countries supplying high-quality 4WD vehicles, automobiles, motorcycles, and marine/internal combustion engines to end-users.

Conclusion – Suzuki Quadzilla LT 500 Review

It may no longer be the fastest stock sport quad in the market, but the Suzuki Quadzilla 500 continues to be revered by racing enthusiasts worldwide. It is just unfortunate that more mechanically savvy sport racers have grown to respect the machine when it is no longer in production.

Without a doubt, the Quadzilla 500 is one dirt-eating beast that is difficult not to love. And until Suzuki resurrects the LT500R, the riding community will remain feeling incomplete – just like the state of Tokyo after the reign of Godzilla.