Designer: Yoshhiharu Nakayama

WITHOUT YOSHIHARU NAKAYAMA, THERE WOULDNƒ??T BE ANY SERIOUS FOUR-STROKES IN MOTOCROSS.

Americans, by their very nature, accept things as they appear. Itƒ??s not that they donƒ??t want to see behind the scenes, itƒ??s just that they like everything wrapped up neatly. Thus, they think that movie actors are actually saying “Make my day” or “Hereƒ??s looking at you, kid.” They donƒ??t want to know that a screenwriter wrote the words and a director told the actor how to say them. They are blissfully ignorant that Tom Cruise is manufactured.

The same is true with motocross stars. They garner all the glory, but behind the scenes, way back in the dark dank corner of the engineering department, is the man responsible for all that success. The unsung hero of professional motocross is the engineer who designed the bike (with nothing more than an idea and a number two pencil). Yes, Virginia, it is true that not every motorcycle designer is a genius, and, as racers know, you have to kiss a lot of frogs to find a prince. But there is one engineer whom every four-stroke rider, regardless of the brand of bike he races, owes a debt of gratitude to. His name is Yoshiharu Nakayama.

Quiet to a fault, Yoshiharu single-handedly launched the modern four-stroke motocross bike. Without Yoshiharu Nakayama, there wouldnƒ??t be any serious four-strokes in motocross. He didnƒ??t just start Yamahaƒ??s motocross four-stroke program, he started everybodyƒ??s four-stroke motocross effort.

“I wanted to change the concept and image of the four-stroke engine,” says Yoshiharu. “I wanted the four-stroke engine to be seriously considered for motocross.” The last eight years have seen Yoshiharuƒ??s wish come true.

A 31-year employee of Yamaha Motor Corporation, Yoshiharu Nakayama directed the development of many YZ projects before the YZ400F, YZ250F and YZ426F. He worked in the same engineering division that developed the Yamaha Road Race and Formula 1 engines (used by the Arrows team). He was the project leader on the 1998 YZ250 and YZ125, 1985 FZ750 and the Engineering Design Leader of the 1994 TZ125, 1992 TZ250, 1990 YZR500, 1990 YZF750 Suzuki 8 Hour and 1990 XTZ750 Paris-Dakar bike. All good bikes, but when they read the roll-call of the greatest motorcycle designers of all-time, Yoshiharu Nakayama will go down as the man who conceived, designed and baby-sat the 1998 Yamaha YZ400 and 2001 Yamaha YZ250F through skeptical bureaucrats at the factory. As hard as it is to believe, the two bikes that jump-started the modern four-stroke movement were not big-budget, corporate-office, full-factory projects. In fact, Yoshiharu designed the YZ250F on his own time! At home! On weekends! And built the prototype with a work force of three!

Amazingly enough, even though the YZ400 was a success, Yamaha execs considered the YZ250F four-stroke to be Yoshiharuƒ??s hobby. They wouldnƒ??t give him a slot in the 2001 production lineup because they didnƒ??t believe that anyone would buy a 250 four-stroke to replace their 125 two-stroke. The rejection of the bike should have been the kiss of death. But, as luck would have it, the American R&D team, led by Mark Porter, was in Japan on the day the YZ250F prototype was being run. They rode it. They liked it. And, most of all, they guaranteed that the rest of the world would buy at least 15,000 unitsƒ?”which was the magic number to get a slot in the production schedule. The rest is history.

But in case you donƒ??t know the historyƒ?”here it is.

(1) Nakayama designed the YZ400ƒ?”which was turned into the CNC-machined works bikes that Doug Henry and Andrea Bartolini raced in 1997.

(2) The success of the prototype led to production of the Yamaha YZ400 in 1998.

(3) Yoshiharu Nakayama made the drawings for the YZ250F in his spare time and, by luck of the draw and happenstance, got it put into production in 2001.

(4) Every other motorcycle company borrowed a page from Nakayamaƒ??s play book and built race-ready four-strokes based on his bore and stroke and overall engine design.

(5) Whether it is a CRF, KX-F, YZ-F, RM-Z of KTM, its wellspring was Yoshiharu Nakayamaƒ??s mind.

And what has happened to the man who launched the modern four-stroke movement with the stroke of his pen? What else? He was promoted to Yamahaƒ??s Motorsports divisionƒ?”a position which, while it takes him away from the drawing board that birthed the YZ400F, YZ426F and YZ250F, gives him first hand interaction with all Yamahaƒ??s racing productsƒ?”including MotoGP. Yamaha couldnƒ??t be in better hands. o