GP’s Classic Steel #60: 1988 YZ250

For this week’s GP’s Classic Steel we are going to take a look back at the bike that started Yamaha’s renaissance in the late eighties, the 1988 YZ250.

For this week’s GP’s Classic Steel we are going to take a look back at the bike that started Yamaha’s renaissance in the late eighties, the 1988 YZ250.

In 1988, Yamaha unveiled the first truly good YZ250 since Jimmy Carter had been in office. Styled after their incredible YZM500 works bike and improved in every way, the new YZ finally made Yamaha a contender once again.

For Yamaha, the early eighties were mostly an exercise in frustration. After dominating for much of the seventies, the boys in yellow had gone into a slump after the retirement of their original monoshock racers. Starting in ’82, Yamaha tried to reinvent the YZ’s with the liquid cooling and rising rate suspension that was all the rage at the time. On paper, they looked up to date and competitive; on the track, however, they left a lot to be desired. Slow motors, grim suspension, porky layouts and quirky handling were all trademarks of these early eighties YZ’s. In 1988, all that would change with the introduction of the most significant Yamaha since the unveiling of the first monoshock YZ, the incredible YZM replica ’88 YZ250.

For 1988, Yamaha’s big signing was two-time 125 National Motocross champion Micky Dymond. Dymond had revitalized his career at Honda, after several tough years on the outdated Husqvarna machines. After delivering two titles in two years, he was surprisingly let go by Big Red. During his stay at Yamaha, Dymond would always look fantastic, but never live up to expectations. In the end, injuries and off-the-track distractions would torpedo Micky’s Yamaha years.

In 1987, Yamaha had taken the wraps off of one of the most exotic works bikes ever with their awesome YZM500 GP racer. The YZM was pure works in a way that had left the US at that point. Everything from its alloy frame to its liquid cooled 500cc motor was 100% works and specific to the YZM. The bike garnered huge press for Yamaha at a time when they looked to be falling way behind their competitors. After spending the first part of the decade in Honda’s shadow, the YZM stole the limelight for a time and bolstered Yamaha’s profile in the press.

For ’88, Yamaha looked to capitalize on all the interest in the YZM with an all-new YZ250. The YZ250 would be a clean sheet design, featuring an all-new motor, revamped suspension and YZM inspired looks. Only the front and rear fenders were shared with the outgoing and unloved ’87 YZ250. It was all new from the ground up, and a chance for Yamaha to finally win back some respectability in the cut throat world of eighties motocross.

At a peak of 36.2 horsepower, the ‘88 YZ was neither the most powerful bike (that honor fell to the KX250 at 40.3 hp), nor the one with the widest power spread (the mellow Honda offered the widest curve, but least excitement), but it was the one with the best motocross powerband. Instantaneous power and a torquey delivery gave the YZ an advantage off the line and out of every corner.

The star of the new YZ250, had to be its racy works-inspired bodywork. The ’88 YZ captured the visual essence of Yamaha’s exotic YZM500 and filtered that down into a production racer. Every piece of the bodywork, save the fenders, was all-new. The tank dropped down “low boy” style around the motor and the seat went all the way up to the gas cap like a works machine. The asymmetrical radiator and massive shroud harkened back to Honda’s unobtanium RC500 works bikes of the early eighties and sweat trickness. The layout was low slung, sleek and offered far better ergonomics than previous YZ designs. In ’87, there were even rumors of Yamaha planning to utilize the YZM’s exotic alloy chassis for the new YZ, but production realities quickly kyboshed that idea. As it was, the YZ offered the visual appeal of the works racer, without breaking Yamaha’s bank account.

The old guard. After an injury plagued 1987, Broc Glover rebounded with a very solid 1988 on the new and much improved YZ. The Golden Boy took a respectable 5th overall in Supercross (winning the season finale in LA) and backed it up with 4th overall outdoors. Even with these impressive finishes and over a decade of loyal service (through good times and bad), Yamaha saw fit to cut Glover loose at the end of ’88. Broc would go on to Europe for ’89, helping to develop KTM’s new “American style” 250, before retiring for good at the end of the year.

Since the introduction of the 1982 YZ250, Yamaha had struggled with the handling on their deuce-and-a-half racers. The YZ’s were top-heavy bikes, with bulky ergonomics and clumsy manners. They had become notorious for their flexy chassis feel, bucking bronco ride and vague handling. In 1985, Dirt Bike Magazine summed up the YZ250’s handling by equating it to a school bus with four flat tires. A scalpel, the YZ was not.

In 1988, you had a lot of choices in the 250 class. If you wanted the best suspension, you bought a Suzuki. If you wanted the most horsepower, you bought a Kawasaki. If you wanted the best-built, you bought a Honda (and wondered what happened to the horsepower you were promised). If you wanted to be different, you bought a KTM. If you wanted to be weird and different, you bought a Cagiva. If you wanted the best bike, you bought the Yamaha YZ250.

For ’88, Yamaha wisely threw the old chassis in the dumpster and started out fresh. The frame was all new and aimed to beef up the previously wimpy chassis’ lackluster performance. While the overall frame retained the previous year’s 28-degree rake and 119mm of trail, the rest of the package was all-new.  There was a larger 52mm steering head and increased diameter on all the frame tubes.  In addition to the beefier frame, Yamaha reinforced the subframe, increased the diameter of the motor mount bolts and repositioned the rear swingarm pivot 5mm lower and 5mm farther forward to decrease chain torque. The last touch was to increase the size and the strength of the swingarm, resulting in a 10mm increase in wheelbase for ’88.

At first glance, the 246cc mill on the new YZ looked to be the same YPVS motor that had been used on every YZ250 since ’82 (with the exception of a silver paint job). In truth, however, it was an all-new design from the ground up.  Everything from the crank to the power valve seals was revised and massaged for better performance.

The result of all this rejiggering was a YZ250 that finally handled. Gone was the rubber-bandy chassis and quirky feel. In its place was a solid and confident platform from which to do business. Steering was sharp, with a planted feel and excellent response (it was not quite as sharp as the class corner King Honda, but a quantum leap better than previous YZ’s). The new low-slung layout allowed the rider to slide much farther forward and better weight the front end in corners. The stronger frame handled hard hits without a wimper and flexed far less than previous designs. At speed, the YZ felt solid and confident, with none of the headshake that scared Honda riders straight into the seminary. In summery, the new YZ best walked the fine line between too sharp and too dull. It was nimble, but not twitchy and stable without being staid. In ’88, this was one sweet handling motorcycle.

From ’82 thru ’87, Yamaha owned the title of worst front suspension in motocross. Every year Kayaba would trot out a new design, with acronyms like VD and TVC, only to end up with the same abysmal performance. In 1988, the arrival of a true cartridge damping system (cartridge damping systems allowed finer tuning and a much larger range of adjustment than the damper-rod systems they replaced) finally heralded the end of the wrist-busting ride that had been the YZ’s trademark for half a decade. Halleluiah!

The other half of the YZ handling equation that was sorely in need of an upgrade was its previously atrocious suspension. In 1987, Yamaha had by far the worst suspension on the track. Its non-cartridge TCV (Travel Control Valve) Kayaba forks were absurdly harsh and punishing on any surface and its BASS (Brake Actuated Suspension System) shock was nearly worthless at absorbing bumps. For ’88, Yamaha finally stepped into the eighties with a true cartridge fork for the YZ. The new 43mm Kayaba legs were a quantum leap above the previous year’s torture devises and on par with the best offered in ’88. They were plush and well damped, with well sorted spring rates. They were smooth on the chop, while still handling big hits well. After five years of grim performance, the YZ finally had a set of forks.

In the shock department, the news was just as good, with the dropping of Yamaha’s dubious Brake Actuated Suspension System (The BASS used a cable attached to the brake lever to lessen compression damping under braking. Its functionality was always questionable and most riders disconnected it all together.). In its place, was an all-new rear suspension system. Gone was the “constant radius curve” linkage of the ’87, replaced with a new more progressive design. The shock was an all-new “Ohlins type” (Yamaha purchased a 50% stake in Ohlins in 1987) damper that borrowed liberally from their new partner. It was smooth and progressive, with good track feel and a plush action. Perhaps most importantly, it finally dispensed with the infamous “Yama-hop” (a tendency early Yamaha’s had to kick suddenly and violently sideways on square edged bumps) that had plagued  Y-Zed’s since the first Monoshocks. With a sweet layout, tight handling and silky smooth suspension, only one thing stood between the new YZ and its date with greatness: its one dimensional motor.

After turning heads in ’87, with a remarkable 2nd overall finish in the 500 Nationals aboard the antiquated YZ490, little know Yamaha support rider Jeff Stanton got the call up to the big leagues for ’88. Jeff would be solid on the new YZ, finishing 10th and 3rd overall respectively in Supercross and the 250 Nationals. After the ’88 season, the Sherwood Michigan rider would be handpicked by Rick Johnson to be his teammate on the powerful Honda squad for ’89.

Originally introduced in 1982, the YZ’s YPVS (Yamaha Power Valve System) motor had held the promise of great performance, but had never quite lived up to its impressive technical specifications.  In the days before “power valves” ( Power valve was a generic term used to refer to the new and varied type of exhaust port gizmos used to alter port timing and exhaust pipe volume to broaden two stroke powerbands) two strokes tended to offer very narrow spreads of power. The new YPVS altered the height of the exhaust port to coincide with engine rpm, and in theory, allowed engineers to offer a wider spread of power from the motor. In practice, the YPVS and its acronymed brothers (The competition was quick to follow suit with their own ATAC, KIPS, AETC and HPP whirligig’s to aid power) rarely lived up to this promise. Most of the time, racing two-strokes still tended to be one-trick-ponies. They were torquers, or they were screamers, but rarely both.

The inspiration for the ’88 YZ’s radical looks came from this rolling piece of moto art. The ’87 YZM500 may be the most exotic bike ever produced by Yamaha. It featured an all-alloy chassis and exotic Monocoquesubframe/airbox. Although its performance on the track never quite lived up to its amazing appearance, it was still an important bike for Yamaha, at a time when they looked to be falling far behind Honda and Kawasaki.

In Yamaha’s case, this power spread tended to be focused mostly in the midrange. In spite of the promise offered by the YPVS, early eighties YZ motors tended to be midrange only, with little useable power at the extremes. They hit hard and pulled strongly, but only for a short period of time. While the Honda CR250R was pulling and pulling, the YZ was always demanding another shift (and a very notchy one at that).

In 1987, Yamaha purchased a 50% stake in Swedish suspension maker Ohlins. As a result, the ’88 YZ benefited from the suspension-makers’ extensive tuning know-how. Although the production shock was still built by Kayaba, its design was by Ohlins and its performance was better for it. When combined with the new bikes more progressive linkage, the “Ohlins style” shock on the YZ provided excellent ride and control.

For ’88, Yamaha made several significant changes, all aimed at widening its narrow power curve. In addition to a spiffy new silver paint job, the deuce-and-a-half Y-Zed received a redesigned YPVS valve that was lowered in the cylinder 5mm and reshaped for better sealing and improved performance. The intake track was also reengineered to allow a straighter shot to the crankcase. The airbox was enlarged and the airboot reshaped for better air flow. The new seven-port cylinder was mated to a high compression head and fed by a 38mm Mikuni mixer. In addition to all the changes to the top-end, Yamaha spec’d a lighter and smaller crank to aid the motor’s responsiveness. In short, Yamaha threw everything and the kitchen sink at the YZ mill for ’88.

In the years before the introduction of upside-down forks, Factory riders often had the option of running the conventional or the USD’s. In this case, Glover chose the conventionals like the stock YZ, while Dymond decided to go the rigid route. The advantage of the conventionals was its more forgiving ride, while the inverted designs offered less axle underhang and reduced flex, at the cost of some comfort.

As a result of all this hard work (and some untimely miss steps by the competition), the YZ ended up having one of the best motors on the track in ‘88. It was ultra-responsive off idle, with “right now” throttle response. It picked up from the slightest crack of the throttle and featured hugely improved low-end power. After its beefy low-end surge, the Yammie pulled into a strong midrange blast that launched it from corner to corner with authority. As in previous years, the YZ petered out on top, but its burly low-to-mid power made the bike fun and fast. Shifting was also marginally improved on the new YZ, with new closer ratios and a redesigned shift mechanism. It was still no silky smooth RM or CR, but it was no longer a notchy nightmare.

With its torquey low-to-mid power and snappy response, the YZ was the quickest bike out of turns in ’88. It came out of the hole hard, hooked up, and transmitted every ounce of power directly to forward thrust. Without a strong top end blast, it was best to short shift the YZ, rather than wring it out in every gear. Riding it like a small Open bike was the best technique on the YZM replica. Keep it a gear tall, carry you speed and throw roost on the others. In the low-end and mid-range, the YZ made the most power and felt the most responsive. It was fun, fast and brutally effective.

One major improvement for ’88 was the addition of the 220mm rear disc brake to the full size YZ’s.  While it was the least powerful of the disc units available that year, it was still far superior to the drum it replaced.

In the horsepower sweepstakes, its closest competition came from the KX250. For ’88, Kawasaki introduced an absolute monster with their new KX250. The bike was big and burly in every dimension and truly felt like a 500. The power came on with such a massive rush that it was actually hard to manage. It cranked out two more horsepower than the next closest 250 (and nearly four more than the YZ) and stomped on the other bikes on top end. Its only flaw was its mediocre low-end, which made the big Kwacker boggy out of corners and harder to manage than the others.  In terms of power, the biggest looser of ’88 was Honda. After dominating the power rankings four out the five previous years, Big Red took a major stumble. The Atlas-booster of ’87 was transformed into the total-snoozer of ’88. It offered a lethargic and mellow delivery that looked omnipotent on the dyno (outclassing all but the KX at  every point), but failed miserably on the track. In the final rankings, it was the snappy Yamaha’s low-to-mid mauler in first, followed by the Top-Fueler Kawasaki in second, mid-range (but much improved) Suzuki in third and the lowly Honda in last.

In the details department, the new YZ was a bit of a mixed bag. On the positive side, were its very good durability, high quality plastic and excellent ergonomics. Its airbox was the roomiest and with its side access, the easiest to service. The addition of a rear disc (finally) was also a plus, although it was the least powerful of the Japanese binders in ’88 (slightly wooden feel and excessive pedal pressure where its major faults).

After their many struggles in the early part of the decade, Yamaha looked to be on the rebound in a major way in 1988. With a hugely improved bike and a stable of hot young up-and-comers like Damon Bradshaw, Larry Ward and Mike LaRocco waiting in the wings, Yamaha looked poised to finally knock Honda off the top pedestal in motocross.

On the not-so-great side of the ledger, were its rock hard chain buffer (This thing clattered so badly you could hear it over the motor when riding!), butter soft and oddly shaped bars (hello Yama-thumb), crappy levers (they preferred to snap off instead of bending in a crash) and hand shredding grips. While the shifting was improved, it was still the least smooth of the big four and offered the wimpiest clutch. The lack of a removable subframe was also a glaring oversight in an all-new design and made the YZ much harder to service than the others.

I owned a 1988 YZ250 (and the 125 as well) and it was a great bike. It had a torquey and snappy powerband, plush suspension and fantastic looks. After half a decade of also-ran status, the Y-Zed was once again a contender. Nineteen eighty-eight was a good year to go white and red.

In 1988, Yamaha hit a total home run with their all-new YZ250. It was fast, tight handling, well suspended and beautiful to look at. It was a $50,000 YZM you could buy for $3099.  The motor lacked top-end, and suffered the occasional missed shift, but overall, it was the best bone stock 250 you could buy in ’88.