YZ 400 Models History
YZ 400 Models History
For the most of the 1970s, Yamaha was the only Japanese manufacturer offering an open-class MX bike. However, the connection dates back much further. You have to go all the way back to Japan's first mass-produced motocross bikes to find out.
Since 1969, Yamaha has been doing so. The 250cc DT1MX and 360cc RT1MX were the official versions that year. They were based on enduro bikes but were scaled down for racing and had factory Yamaha GYT equipment.
Those early motorcycles became the basis of racing operations in Europe and the United States. Torsten Hallman was the focal point of a global development program that used the World Championship Grand Prix as a testing ground.
The riders were Gary and DeWayne Jones, and their father, Don Jones, was the engineer.
Both factions took their reinvented race bikes to Japan, where they were met with all-new, entry-level motorcycles released to the general public in 1973. That was the commencement of the YZ line.
YZ 400 Models History By Years
In Europe and Canada, the first YZs arrive in 1973. They used straps to fasten their lightweight metal gasoline tanks. Gary Jones admits that the prototype was made with saddle straps fashioned from horse tack shop materials. The straps were so popular with the Japanese engineers that they were included in the manufacturing model. Yamaha sold an oddball model named the SC500 in the United States that was unrelated to anything marketed prior or later. The SC was powerful, but it was a challenge to ride. In the same year, the US had an MX360 based on the RT1 enduro bike.
In 1974, America received the entire YZ series, including the 360, 250, and 125. Yamaha also maintained its MX series, which was more cheap. These were also new bikes, but they had nearly no parts in common with the YZs. The YZ360A cost roughly $1700 in the United States. There were only 500 manufactured, and the '74 YZ360A is still one of the most sought-after vintage dirt bikes.
In 1975, long-travel suspension swept the motocross world. In Yamaha's case, this signified the Monoshock was on the way. Yamaha continued to provide two distinct lines: the huge YZ remained 360cc, while the new MX400 had a 397cc displacement. Although the MX was heavier and less expensive, most riders preferred it to the pipey YZ360.
Yamaha, sort of, ended the MX line in 1976. The new YZ400 was based on the MX400 from 1975. Large reservoirs at the top of each fork leg were added to the 1976 version, which cost extra. Each year between 1976 and 1978, the YZ400 improved.
In 1977, it received a plastic fuel tank, and in 1978, an aluminum swingarm. The YZ400E from 1978 is widely regarded as one of the top Open-class MX bikes of the decade. In 1976, the TT500 was also released. It was Yamaha's first dirt-only four-stroke motorbike, and it became an instant classic.
In Japanese motocross, 1979 was a year of backward progress. The 1979 YZ400 was revamped with a short-stroke motor that wasn't as powerful as its predecessor. This allowed European manufacturers, primarily Maico, to re-enter the fray. In the Open class, Honda and Kawasaki had nothing, while Yamaha and Suzuki were unprepared for the arrival of the Maico 490. Yamaha added an IT400 to the IT range of off-road motorcycles.
1980–81: Yamaha rapidly responded to the situation by introducing the YZ465. In every sense, it was a fantastic bike. If Yamaha had persisted with that engine, the Open class might have been rescued for years. However, a horsepower race was brewing. For a year, the IT400 became an IT425 and eventually an IT465. It would be phased out in 1985.
Yamaha introduces the YZ490J in 1982. It received a major change to the Monoshock design, which now includes linkage between the shock and the swingarm, in addition to the increased displacement. The 490 was big, swift, and demanded a lot from its rider. Unfortunately, the Open class in motocross was beginning to fade, and Yamaha didn't see a compelling reason to continue developing the huge two-stroke.
From 1983 through 1990, the YZ490 was a strong and fearsome motorcycle, but development slowed to a halt. The '83 model received a new suspension design, and the '85 model received a front disc brake and a Euro-style white color scheme, but little else changed. Meanwhile, both the Honda CR500R and the Kawasaki KX500 acquired liquid cooling, but sales and development stagnated. When the YZ490 was quietly discontinued in 1991, it was essentially obsolete.
1992: For a two-year life as an off-road bike, the 490 was revived as the WR500. The WR received a larger gasoline tank as well as a number of off-road features. It didn't go over well with racers, but it was a hit with the sand-dune crowd.
The YZ400F ushered in the four-stroke era in 1998. It wasn't quite as good as the two-stroke at the time, but it came close. The YZ426 from 2000 was only somewhat better, but it was still difficult to start and heavy.
2003: It was evident by this point that four-strokes were going to take over. It had only been a matter of time. The YZ450F emerged as a counter to the Honda CRF450R in 2002, reigniting the horsepower rivalry.
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