Valentino Russi's 04 YAMAHA YZF-M1 Simply the best

Exclusive track test at Valencia two days after final GP of season, of the factory Yamaha YZF-M1 MotoGP racer on which Valentino Rossi beat Honda to win the 2004 World Championship – his first of four World titles for Yamaha

Valentino Rossi’s deservedly acclaimed 2004 triumph in handing Yamaha its first premier-class GP Riders’ World Championship in twelve long years, achieved just what he’d always said he aimed to do when he walked out on Honda twelve months earlier - mainly because, he said, of HRC management’s insistence on diminishing the role of the rider (namely, himself!) in developing Honda’s V5 MotoGP racebike, and winning races with it. Walking across the street to a Yamaha Racing operation desperate for success with its hitherto underachieving YZF-M1 in-line four and turning it into a world champion, was a big ask. But, one year on, with the close support of Yamaha’s new race boss Masao Furusawa, the lovable Latin had taken the Japanese firm’s race operation by the scruff of its neck and delivered exactly what he’d said he’d do - beat Honda.

Revenge is a dish best enjoyed cold - and it was all the sweeter for Valentino because of the manner in which it was obtained, winning the first of nine MotoGP race victories on his debut ride for Yamaha in South Africa, en route to clinching the title one race early in Phillip Island. Mission accomplished.

The chance to discover from the hot seat exactly how Rossi and the Yamaha factory race team had turned the lack-luster YZF-M1 which I found less than impressive when I’d first ridden it one year earlier, into such a dominant title-winning 2004 package, came in a pair of 15-minute test sessions at Valencia two days after Valentino had swept to victory there in the final GP of 2004 - a race he didn’t have to win, remember, with the title already wrapped up. After talking to him about the M1 the previous week at Yamaha’s R6 launch at the same circuit (see sidebar), I’d been counting seconds until I could finally throw a leg over his 2004 World champion ultra bike - The Bike That Valentino Made, with a little help from Yamaha, and Jerry Burgess and his crew. For this title success was indeed very much a team effort.....

First though, just beforehand, I’d spent five laps getting reacquainted with Loris Capirossi’s V4 Ducati Desmosedici - about as different a motorcycle from the less powerful but much more refined-feeling Yamaha, as could possibly be imagined. These two bikes were at opposite poles of MotoGP race development back then, and after hopping off the muscular, mighty, so-fast but so-flighty Ducati, which seemed eager to spin the standard rear Michelin we’d been assigned for our press tests at almost any revs in each of the bottom four gears, and needed heaps of physical force and body English to wrestle it from side to side in Valencia’s tight turns, walking up pit lane to straddle the Yamaha, seemingly so delicate and refined by comparison, was like looking at a Swiss watch to tell the time, rather than Big Ben!

The Yamaha felt lower and smaller to settle aboard than the Ducati, which you sat in rather than on, surrounded by bodywork, and though it was a touch wider than the V4 Suzuki I’d been riding at the same circuit the week before the GP, the YZF-M1 felt less tall and more wieldy than the GSV-R. Even compared to the ZX-RR Kawasaki I’d tested the previous day - also an in-line four, remember, and whose Suter-build frame was much more compact than 2003’s Incredible Hulk - the YZF-M1 felt slightly smaller, if a little longer, than the Green Screamie. That was the bike it was closest to in architecture, though - not only in terms of chassis design but also because of the engine layout which was now very close to the Kawasaki’s, after Yamaha switched to a similar 16-valve layout from January onwards, from the five-valves-per-cylinder format used previously.

Watching the Yamaha mechanics fire the YZF-M1 up with an ingenious rear-wheel trolley starter which didn’t require them to lock the slipper clutch in place to do so, as Ducati must (so presumably they use a higher degree of ramp angle to achieve this), was the signal to hop aboard and head off down pit lane, after first noting the M1’s quite high 3,000 rpm idle speed at rest, and the so-distinctive gruff engine note of the in-line four-cylinder motor with its closed-up firing order adopted for that season, compared to the previous year’s evenly spaced Kawasaki-like screamer. Next surprise: unlike any of the other MotoGP bikes, even the super-Superbike Suzuki, the Yamaha drove cleanly away from the mark almost as easily as a road bike, without any need to wind up the clutch, nor any transmission snatch, holes in the powerband, surging of revs or jerky throttle response. It just got up, and went with minimal fuss, just very fast - thus putting Valentino’s unaccustomed good starts that season into perspective, because it was such a controllable but responsive bike to get off the line when the flag dropped. The Magneti Marelli EFI adopted on the bike from mid-season, had a programme which restricted revs to 5,800 rpm in first gear after firing up the motor, good for the 80 km/h pitlane speed limit - until you changed into second gear for the first time, after which it was wiped so you could use full revs in first gear, if you decided you had to do so (and you did, twice per lap, at Valencia).

Out on the track, it’s best to explain what Valentino’s World champion 16-valve YZF-M1 was like to ride by telling you first of all what it didn’t do, especially compared to Checa’s flawed 20-valve ‘03 bike I’d ridden a year earlier. So, it didn’t wheelie anymore in the bottom four gears out of Valencia’s final turn on to the pit straight, reaching repeatedly for the sky as you tried desperately to keep the throttle wound wide open as you powershifted up the gearbox with the front wheel waving around your ears. It didn’t freewheel into corners like before, with all engine braking programmed out just to satisfy the unreformed 250GP two-stroke riders who were previously responsible for developing and racing the YZF-M1, while still grappling to come to terms with such an alien concept. Neither did it still back into turns thanks to a flawed weight transfer, when you squeezed hard on the front brake lever and stamped on the rear stopper. Nor when you got back on the throttle to exit a turn, did it snap away from your chosen line owing to the aggressive power delivery of the flatslide throttles fitted previously, instead of the smoother, more user-friendly twinbutterfly design Furusawa-san said was used now, and nor did it skip about over bumps thanks to a too-stiff suspension package, all of which it did before.

SPECS 04 Yamaha YZF-M1

Engine: Watercooled dohc 16-valve transverse in-line four-cylinder four-stroke with offset composite chain and gear camshaft drive

Dimensions: Unknown

Capacity: 990 cc

Output: Over 240 bhp at 15,000 rpm (at crankshaft)

Compression ratio: 14.8:1 approx.

Fuel/ignition system: Electronic fuel injection and engine management system, with Magneti Marelli ECU, two injectors per cylinder, two optional EPROM maps and four ??mm Keihin throttle bodies with dual butterflies

Transmission: 6-speed cassette-type extractable

Clutch: Multiplate dry ramp-style slipper-type

Chassis: Aluminium Deltabox twin-spar frame

Suspension: Front: 42mm Ohlins inverted telescopic forks

Rear: Machined aluminium swingarm with Ohlins shock and rising rate linkage

Head angle: Adjustable

Wheelbase: N/a

Trail: Adjustable

Weight: 148 kg with oil and water, no fuel

Weight distribution: 56/44% static

Brakes: Front: 2 x 308mm or 320mm Brembo carbon discs with four-piston radial Brembo calipers

Rear: 1 x 220 mm Yamaha ventilated steel disc with two-piston Brembo caliper

Wheels/tyres: Front: 12/60-420 Michelin on forged Marchesini wheel Rear: 19/67-420 Michelin on forged Marchesini wheel

Top speed: 339 kph (Mugello 2004)

Year: 2004

Owner: Yamaha Motor Company, Iwata, Japan

Instead, this was a motorcycle which inside one lap you recognized had been transformed from a bad-tempered bulldog of an in-line four to a vastly more sophisticated feeling, refined thoroughbred which worked with the rider rather than against him, and asked you what you wanted from it, rather than telling you this was the way things are gonna be, so get used to it! It’s as if the computer was no longer in charge of things, but now the rider was, and that was especially true of the engine braking, which a) now existed and b) felt perfectly set-up, so there was just enough there when you braked hard and backshifted for a turn like Turn One at Valencia to make you realize the Yamaha was now working with you, rather than against you. There was a far more direct connection between throttle and back tire than before, too, much better than the Ducati and especially the Kawasaki, where the barely controllable fierce surge of acceleration when you got back on the gas after slowing for a turn, was very disconcerting and invited you to run wide if you weren’t ready for it, as well as spin the back wheel. The Suzuki GSV-R was like the Yamaha in having The Connection, but it was also at least 25 bhp down on power compared to the YZF-M1, so maybe there was a reason for that! This linear power delivery made the Yamaha very controllable and responsive in terms of handling so that it turned more tightly and held a line better than before, without the sense of instability you had on the previous year’s bike when the power got switched on again by the ECU after you’d freewheeled around a turn on the overrun!

Despite the irregular firing order Yamaha introduced that season to improve traction and acceleration, the YZF-M1 engine felt even smoother but no less vivid in terms of engine pickup than in 2003, driving hard from as low as 8,000 rpm. That was thanks to the intermediate shaft positioned between the crankshaft and clutch, to allow the engine to turn backward, now containing balance weights to act as a counterbalancer. There were no undue vibrations of any kind, which must have helped make this a relatively untiring bike to ride for a 45-minute GP. Instead, it was sweetly responsive almost anywhere in the powerband, and especially from 9,000 rpm upwards, en route to the 15,000 rpm rev limiter (500 rpm lower than the year before, presumably thanks to the 16-valve layout’s bigger, therefore heavier, titanium valves). There was a wakeup call at 14,500 rpm when the big red junior searchlight on the dash and the row of orange lights beneath it told you to shift up right NOW on the wide-open race pattern power shifter, but overall the Yamaha’s fabulously refined power delivery wasn’t just smooth and, at 240 bhp-plus, extremely potent – it was also predictable, and controllable.