In 1996, Yamaha introduced the completely new YZ125 model - the best one since 1980, leaving behind years of disappointment for brand enthusiasts.

Today, the Yamaha YZ125 remains one of the few 125cc two-stroke motorcycles still in production. It represents a nostalgic breeze from another era when motorcycles were lightweight, easy to maintain, and a joy to ride. A time when the sweet scent of castor oil filled the morning air, and the distinctive sound of a two-stroke engine echoed on tracks worldwide. Sadly, that era of intense competition and annual model releases is now a thing of the past.

Over the last fifteen years, the YZ125 has consistently been one of the top-performing 125cc models, remaining competitive and rivaling the Austrian trio to this day.

The 1980s were a period of disappointment and editorial criticism for Yamaha's YZ125. Slow engines, subpar suspension, and a poor frame placed the YZ125 at the bottom of most buyers' wish lists for over a decade.

By the late 1980s, the YZ125 received a much-needed development boost: a new engine and modified frame. The new motorcycle was moderately fast but suffered from a narrow powerband and a terrible gearbox. By the early 1990s, it had unquestionably the worst engine in its class, making it so non-competitive that racers steered clear of Yamaha.

In 1991, Yamaha, one of the strongest brands in motocross at the time, unveiled an entirely new YZ125, hoping to reclaim the long-awaited 125cc class title. The new model featured bold styling and a more vibrant appearance compared to its predecessors.

After a challenging period in the early 1980s, the brand swiftly returned to stylish design and impressive performance. While the glory days of Brock Glover and Bob Hannah were already in the past, a new star emerged in 1989 - Damon Bradshaw, on whom the team placed high hopes. He clinched the AMA Supercross 125SX Eastern Region title for Yamaha in his debut professional season, bringing the brand back into the limelight.

In 1991, Yamaha, still a dominant force in motocross, sought to improve the YZ125 model, but their efforts ended in colossal disappointment.

The changes primarily affected the engine. They installed new components such as the cylinder, head, ignition, reed valve, and an upgraded YPVS exhaust system in an attempt to boost high-end power. Unfortunately, the engineers' pursuit of more power resulted in a dull engine and a "sluggish" motorcycle that couldn't even match the performance of the 1984 KX125. Dissatisfied riders compared the new motorcycle's performance to that of the 1985 YZ125, making it practically useless for racing. Despite modifications to the reed valve and carburetor, the problem persisted. It was undoubtedly the slowest YZ125 since 1985, and its engine was almost worthless for competitive racing.

Testers from "Dirt Bike" magazine described an intriguing fact about this motorcycle: "In the summer of 1990, we were invited to test the 1991 YZ125, and honestly, we were impressed with its engine characteristics. However, after the production release and testing of the purchased motorcycle, we were baffled by how different the engine had become. The difference between the test model and the production version was simply enormous. It remains a mystery to us, and Jim Holly is still scratching his head over this question."

However, while the production version of the YZ125 left something to be desired in terms of the engine, the factory version proved to be outstanding. Jeff Emig, riding the factory YZ125, was one of the fastest in the country, easily securing "holeshots" on this motorcycle in both supercross and open tracks.

Although the engine on the standard model turned out to be a major disappointment, the rest of the motorcycle's components were quite solid. Kayaba provided an improved shock with additional adjustments, increased the fork travel, and enlarged the tube diameter from 41mm to 43mm, which undoubtedly improved the bike's handling. The bike also featured a new swingarm that was both lighter and more reliable than previous models, while maintaining excellent stability and maneuverability. On fast and rough tracks, the YZ outperformed all competitors, but riding it in muddy conditions was a real challenge. The bike also struggled to compete on clay and sandy tracks, but in terms of quality and reliability, it fell short only compared to Honda, surpassing Suzuki and Kawasaki. With a different engine, this motorcycle would have been quite impressive, but it remained an unfulfilled hope for Yamaha's engineers.

In 1992, the Yamaha YZ125 underwent numerous changes, immediately noticeable in its appearance. The bike featured new graphics, a more modern front fender, and front number plate panel. It also received an enlarged 245mm front brake disc, a new front fork, rear shock absorber, rear tire, and footpegs. Changes also extended to the engine, exhaust system, and the installation of larger radiators. The following year, the YZ125 received a completely new plastic design and graphics, as well as a revised fuel tank and frame. The engine underwent minor changes, and in this year, it became the last engine based on the 1986 model.

In 1994, Yamaha finally demonstrated that they had something significant to offer and introduced the YZ125 model with an entirely new engine. When designing the new engine, the company's engineers abandoned the original "drum" power valve mechanism YPVS, first used in the 1982 YZ125, and replaced it with a design similar to Suzuki's second-generation ATEC. The new design featured a set of guillotine-type valves that slid up and down depending on the engine's RPM. By opening or closing these valves, engineers could alter the exhaust port timing to achieve a broader power distribution. While this concept resembled the outdated YPVS, the new system had tighter tolerances to enhance performance.

Although the new engine was a crucial step in the right direction, it still wasn't enough to propel the YZ125 to the top. Despite improving the previous power range, old issues such as abrupt gear shifts and a lack of top-end power persisted. In a class dominated by the Honda CR125 with its wide powerband and extended top-end pull, Yamaha's short power range remained a significant drawback.

In 1996, Yamaha unveiled an entirely new YZ125 model, signaling the end of a disappointing era. Engineers started from scratch, redesigning the motorcycle with a new frame and rear suspension layout, resulting in a reduced wheelbase and more weight concentrated in the front. The new front fork received stiffer springs, and in addition to that, the bike featured a new exterior design and significantly improved ergonomics.

Most importantly, the model underwent numerous changes in the engine to expand its power range. After several years of underpowered engines, Yamaha finally made the necessary adjustments. The new YZ125 engine boasted an incredibly wide power range, excellent torque, and a considerable boost in horsepower.

It's worth noting that the engine retained the same basic design Yamaha had used for the past two years, but several critical changes were made to enhance performance. First, the crankshaft was reworked, reducing the crankcase volume for increased primary compression and better low-end torque.

To maximize peak performance, the YPVS system valves were massaged for improved sealing and expanded by 2.5 mm. Compression was also lowered from 9.2:1 to 8.5:1, and the ignition timing advance was slightly increased compared to the 1995 model, ensuring freer revving at high RPMs. The new piston was both stronger and lighter (by 18 grams), a new reed valve was installed, and the bike was equipped with a 36-millimeter Mikuni TMX flat-slide carburetor. In the transmission, new shift forks promised to resolve the infamous third-gear shift issue that plagued Yamaha.

Now, the new YZ125 engine had a wide powerband, resembling that of a 250cc model. It delivered exceptional low-end torque and strong mid-range pull, while the top-end performance was better than that of the Honda. The result was the most powerful and best-performing engine in Yamaha's history. In short, the new YZ125 was an absolute revelation in 1996, finally becoming fast, lightweight, and well-handling after two decades of mediocrity. For many years, Yamaha managed to produce some fast YZ125 bikes with good power ranges on paper, but they always fell short of what racers needed. All of that changed in 1996 when engineers finally crafted the best engine in the class.

The torque at the start was outstanding, followed by a strong burst in mid-range RPMs. The power in the top-end was decent, although not as impressive as that of the Honda CR125R. The engine could sustain a long pull on a single gear and boasted the widest power range in its class. From 7000 RPM to 11,000 RPM, it outperformed the competition, providing a three-horsepower advantage.

Regarding the suspension, Yamaha received an entirely new fork. In 1996, the trend was leaning towards soft forks, and Suzuki and KTM were praised for their ultra-soft suspensions. However, Yamaha went in the opposite direction and sought to increase the stiffness in its front end. The new Kayaba fork featured an increased tube diameter, going from 43mm to 46mm, adding stiffness and allowing for a larger cartridge, base valve, and mid-valve damper. The addition of new clamps with dual pinch bolts, an increased overlap area on the clamps, and a larger front axle contributed to the enhanced stiffness.

In terms of performance, the YZ125 fork was superior for lightweight riders but too soft for heavy or fast riders. With standard springs, the fork easily bottomed out on hard hits, necessitating stiffer springs for quicker riders. On the other hand, most riders found it easy to adjust the fork using the available settings. Ultimately, Yamaha's fork ranked as the second-best in the class, coming close to Suzuki's suspension.

From 1993 to 1995, most riders found the rear suspension of the YZ125 acceptable but not attractive. Many complained about the tendency of the linkage system to sag down at the end of its stroke and become too aggressive when handling medium impacts. To address this issue, many riders replaced the stock link with Noleen or DeVol products. These aftermarket solutions offered a revised rising rate that prevented the rear end from sagging excessively under acceleration.

In 1996, Yamaha responded to these complaints by introducing a completely new rear suspension design. In the new "Monocross" system, the pivot point was moved from under the swingarm to the midsection of the swingarm, similar to Honda's design. A new, larger and stronger swingarm was developed, attached to the swingarm by bolts, which initially had more stiffness in the first 100mm of travel, then mimicked the previous year's suspension for the remaining travel.

On the track, the new YZ125 had a very smooth ride. The movement was cat-like soft, and the suspension effortlessly absorbed small and medium impacts. Just like with the front fork, it was recommended for faster riders to increase the rear shock spring's stiffness to prevent bottoming out on big jumps. Overall, the rear suspension was considered best suited for lightweight riders but was deemed too soft for heavier or faster riders.

In 1996, Yamaha abandoned the frame design used since 1993 and developed an entirely new platform. The new frame had greater stiffness, reduced trail (3mm), increased ground clearance (12mm), a shorter wheelbase (16mm), and more weight shifted towards the front. The new plastic also improved ergonomics and handling, giving the motorcycle a flatter and thinner layout that allowed the rider to move forward and backward with less effort. Interestingly, despite Yamaha completely overhauling the frame, the bike ultimately handled more or less the same as its predecessor.

On fast sections and rough straights, the YZ125 inspired confidence and handled better than the CR125. There was no hint of "headshake," and the bike never did anything strange or caught the rider off guard. Overall, it was a solid machine that amplified what people liked about Yamaha's handling but didn't entirely appease the critics.

Regarding details, the new YZ125 succeeded in some areas and took a step back in others. The new Akebono brake components significantly improved braking power and, for the first time in a decade, provided competition for Honda's brakes' dead grip. Overall, the new plastic and appearance received high praise from test riders, but some racers missed the integrated grab handles from the 1995 model for easier bike stand setup, while others complained that their braces caught on the rear radiator shrouds. The standard handlebar was soft as butter and didn't particularly impress anyone with its low and steep "old-school" bend back. The new dark blue color scheme marked a significant change from the lightning design of 1995, and most riders welcomed the new appearance.

Though the new YZ125 was undoubtedly the company's best machine in almost two decades, there were still issues with the completely new design. The most significant concern was reliability. The new transmission was a major problem; while shifting was slightly improved, it had an irritating tendency to skip gears. MXA and Dirt Bike Magazine both experienced transmission failures in their test bikes, and numerous racers reported similar issues.

Standard wheel hubs also posed a serious problem, and broken hubs were a common occurrence. While these issues were annoying, they could be resolved relatively easily (albeit expensively). Overall, the YZ125 had seen significant improvements but was far from perfect.

In conclusion, it can be said that in 1996, Yamaha presented its best 125cc model since 1980. While it still had some problematic areas that needed attention, it was the best in the one aspect that truly mattered in this class - engine power.

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