Machines that forged the way to the modern sport quad By the staff of Dirt Wheels

We can always find something great to say about every ATV put out by a major powersports manufacturer. Some are recognized for engine performance, while others for suspension action and adjustability. Many are tailored for the trail warrior looking for an all-day comfortable ride, while others are bred for motocross and cross-country racing.

Then there are the trendsetters—the ATVs that altered the map towards today’s modern sport quad. We’re talking about the three- and four-wheelers that brought innovation to the powersports market with new features like liquid-cooling, aluminum chassis, electronic fuel injection and, yes, the introduction of a fourth wheel. These are the machines that we will focus on for this list, beginning with the three-wheeler that started it all.


The ATC made its American debut in 1969 with the introduction of the US 90. Around 1967, American Honda requested a new product that would help boost sales in the winter months when motorcycle sales were typically low. Honda engineer Osamu Takeuchi spearheaded the project, which resulted in a three-wheeled chassis driven by a 7-horsepower, 89cc, air-cooled four-stroke engine with a recoil starter. The 4-speed transmission offered high- and low-range operation, getting power to the wheels with an enclosed chain drive. 

The standout feature on the US90 was the 22-inch balloon tires, which doubled as a suspension system. The tires were designed to run with very low air pressure, softening the hits from rugged terrain and providing optimal traction in sand, snow and mud. The US90 was an instant hit with consumers, and even made a cameo appearance in the 1971 James Bond film, “Diamonds Are Forever,” with Sean Connery at the controls.

In 1974, Honda changed the name to the ATC90 to be uniform with its other three-wheeled offerings. The balloon tires also gave way to more aggressive knobby-style tires, and the chassis was redesigned for more strength. Honda kept this design in play until the ATC90 was discontinued in 1978.


Honda ATC185S

Recognizing the market demand for recreational three-wheelers, Honda made some big changes to the more utility-focused ATC185 that it had just introduced in 1980. For the 1981 model year, Honda reduced the tire size from 25-inch tires to a slightly more aggressive knobby design in a 22-inch size. The wheelbase was also shortened up by 1.6 inches and overall weight decreased by 32 pounds, making it more maneuverable on the trail. The “S” was also added to the model’s name, signifying the sportier temperament. 

The 1981 Honda ATC185S was introduced as a sportier and more recreational-focused version of the 1980 ATC185 with smaller knobby tires, a shorter wheelbase and reduced weight.

Returning features included a 180.2cc air-cooled engine with a semi-auto clutch 5-speed transmission. The 1981 ATC185S also greeted consumers with a sticker price that was $100 less than the previous model. The 185S remained as part of Honda’s three-wheeler lineup until 1983. Later models gained front suspension. Forty years later, there are still plenty of ATC185S three-wheelers out there that run just as strong as they did on day one—a testament to Honda’s track record of reliability.


In the 1980s, three-wheelers soared to a whole new level of acclaim with bigger and more powerful engine choices. Once again, Honda led the charge with its introduction of the 1981 Honda ATC250R. The first-generation ATC250R (1981-1982) got its power from an air-cooled two-stroke engine like the one used in Honda’s popular CR250R dirt bike. It had limited suspension that partially relied on balloon tires and low air pressure to cushion the ride.

The second-generation ATC250R (1983-1984) saw competition from the likes of Kawasaki (Tecate 3) and Yamaha (Tri-Z 250), as well as a few U.S. home-grown startups. Honda upgraded the ATC250R to be more comfortable with a longer wheelbase, wider stance, increased distance from seat to footpegs and taller handlebars. But, the biggest change came in the form of suspension with the introduction of Showa forks and the all-new Pro-Link rear end. Three-wheeler racing skyrocketed in popularity as Team Honda racers ruled at the track and in the desert. The competition became fierce, and Honda was determined to make the ATC250R even better.

In just six years, Honda’s ATC250R two-stroke three-wheeler went through three major generational changes and made history as the first true high-performance ATC.

In 1985 Honda released the third generation (1985-1986) of the ATC250R with a complete redesign. The engine was updated with more power, liquid cooling and mated to a 6-speed transmission. Suspension got a major upgrade in plushness, which allowed Honda to trade out the old balloon tires for a lower-profile tire that was more aggressive and competitive at the track. This third-generation ATC250R is arguably the best high-performance three-wheeler ever created by a major manufacturer.


In 1982 Suzuki introduced the first four-wheeled ATV to consumers with the LT125 S, an entry-level sport ATV with a 125cc four-stroke engine and 5-speed transmission with a semi-automatic clutch.

In 1985 Suzuki increased displacement and size with the LT230S QuadSport. This machine defined the future of sport ATVs with features like double-A-arm front suspension, a solid rear axle, and disc brakes front and rear.

Suzuki earned the phrase “first on four wheels” when it introduced the QuadRunner LT125 in 1982. It followed that up with the QuadRunner LT230S and the high-performance QuadRacer LT250R.

That same year Suzuki also introduced the first high-performance sport quad—the LT250R QuadRacer, which ushered in the beginning of four-wheeled ATV racing. It was fitted with a 249cc, liquid-cooled two-stroke engine and a 5-speed manual transmission. The front independent A-arm suspension was set up with oil-damped, five-way preload-adjustable shocks. At the rear, a swingarm and straight-axle design incorporated a single preload-adjustable shock. 

The LT250R QuadRacer remained part of the Suzuki ATV fleet through 1992. It saw several changes during that time. The biggest update happened in 1987; the engine was redesigned with a power valve for greater acceleration, a 6-speed transmission was installed, the chassis was strengthened, and the seat was widened into the classic Suzuki T-shape for added comfort.


Honda wasn’t the first player in the four-wheeler game, but it came to the table with guns blazing. For the 1986 model year, Honda released the TRX250R, arguably the best sport quad ever created and undeniably the most influential. The TRX250R had it all—light weight, smooth handling characteristics, excellent ergonomics and plenty of two-stroke power on tap. Front independent A-arm suspension was teamed with a rear swingarm and Showa shocks all around to provide optimal wheel travel.

Honda’s TRX250R defined the future of sport quad design with features that were mimicked by competing manufacturers for decades.

In 1987 the chassis remained essentially the same, but the engine received power upgrades in the form of a longer connecting rod, slightly higher compression ratio and a bridged intake port. 1988 saw even bigger changes with a shorter wheelbase to further enhance turning. The body plastic and fenders also took on a different look with the headlight moved to a fixed position in the nose piece. Overall weight also decreased by 27 pounds, giving the Honda a nimbler feel.

While the TRX250R was only produced until 1989, it remained the dominant player at the racetrack well into the next century when modern four-strokes took over.


While Suzuki, Honda and Kawasaki turned to their dirt bike roots for four-wheeler engine inspiration, Yamaha went an entirely different direction—its RZ350 “café racer” street bike. 

The RZ350 got its power from a 347cc two-stroke twin cylinder with a power-valve system. A new version of the engine was developed for the Banshee without the power valve but retained the twin-parallel cylinders fed by dual 26mm Mikuni carburetors. It lacked nothing for power and still packed a wheel-raising mid-range hit. While not exactly designed for track use, the Banshee immediately racked up a desert racing pedigree with wins in Baja. 

Not wanting to be outdone, Yamaha took a completely different approach when designing the 1987 Banshee. To this day, the wild ride provided by the parallel-twin two-stroke is legendary.

The Banshee was first introduced in 1987 with an upper J-arm front suspension that was susceptible to damage. In 1991 the J-arms were converted to much stronger A-arms.

In the late ’80s and ’90s, the Yamaha Banshee was the go-to for dune riding, visible all over sandy OHV areas, much like side-by-sides are today.

In 2006, Yamaha ceased production of the Banshee in the USA, but it remained available in Canada until 2008 and Australia until 2012.


Exactly 10 years after Honda’s TRX250R was discontinued, word got around that it had a replacement, the 1999 TRX400EX. It didn’t take long for racers to determine that this wasn’t the race machine that they were looking for, as the two-strokes and hybrid race machines continued to dominate at the MX track.

While Honda was the first manufacturer to introduce a 400cc four-stroke sport quad, Suzuki trumped it with its own liquid-cooled version and an ATVMX National Championship.

Then, in 2003, Suzuki launched its own 400cc four-stroke that included something the Honda didn’t—liquid cooling. Many claim that machines like the Honda TRX450R and Yamaha YFZ450 launched the modern four-stroke movement, but it was the LTZ-400 that got the ball rolling. The same year that the LTZ-400 hit dealership floors, Doug “Digger” Gust won the ATVMX National Championship, a first for a four-stroke ATV.


For Honda fans and racers, the 2004 TRX450R was the sport quad they had been longing for. Taking technology from the recently released CRF450R dirt bike, the new Honda sport quad had explosive power and well-matched suspension. 

Honda’s TRX450R sport quad was discontinued in 2014, but it continues to dominate the West Coast ATV racing scene to this day.

In 2006, the TRX450R received a power boost with a larger bore, shorter stroke, significantly increased engine compression and a new Keihin FCR carburetor. The changes also allowed an increase in maximum engine rpm. That same year Honda also introduced an electric-start version, the TRX450ER.

The TRX450R won championships in pretty much every ATV racing discipline, including MX, XC, desert racing, Baja, ice racing, flat track, and the list goes on. The TRX450R was discontinued in 2014, but it continues to dominate the West Coast racing scene to this day.


As easy as it is to ride, most would never guess that the Raptor 700R produces more power and torque than a 450cc racer. If you’re looking for a new Open-class sport ATV, the Raptor 700R is your only option, but with features like electronic fuel injection, fully adjustable shocks and a hybrid steel and aluminum frame, there’s little left to complain about.

Strong horsepower, gobs of torque, infinitely adjustable suspension and all-day comfortable ergonomics are the reasons that Yamaha’s Raptor 700R is the best-selling sport quad of all time.

It remains the best-selling sport quad of all time. Even when it had competition from the likes of KTM (525XC), Honda (700XX) and Polaris (Outlaw 525S and 525 IRS), the Raptor 700R rarely ever placed below first in any magazine shootout.

For the recreational trail rider and duner looking for a powerful ATV that offers an all-day comfortable ride, the Raptor 700R never disappoints.


2004 was a great year for sport quad fans and racers alike. In addition to Honda’s new TRX450R, Yamaha released its all-new YFZ450. It was an instant hit with its high-revving modern four-stroke engine, fully adjustable piggyback reservoir shocks and gullwing-style A-arms.

In 2009, Yamaha released two completely redesigned models that were practically race-ready. Both received engine upgrades, electronic fuel injection, an all-new steel/aluminum hybrid chassis, four-way-adjustable ProTaper handlebars and upgraded suspension. The YFZ450X was designed for woods racing with its narrower stance, and the YFZ450R was built for motocross at nearly 49 inches wide.

In 2004 Yamaha introduced us to its new YFZ450, which only got better as years progressed. The YFZ450R remains the only new choice for sport quad racers.

For racers, the YFZ450R is the pinnacle of performance. One need not look farther than the most current point standings of the GNCC and ATVMX racing series to see that Yamaha’s YFZ450R is the dominant choice of today’s top pro ATV racers.

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