The story of the Yamaha YZ 250 2T.27 October, 2016
The story of the Yamaha YZ 250 2T.
Yamaha YZ250 The family is part of motorcycle cross YZ. It premiered in 1975 and it was the first off-road bike with a single rear shock. Innovation resulted in significant changes in the way the motorcycle manufacturers suspension systems manufactured off-road bike. Unlike many motorcycle two-stroke motocross, Yamaha constantly updated YZ250, also, He took first place in classic off-road triumphs as the American Motorcyclist Association 2009 National Hare Scramble.
The YZ250 has its roots in motorcycle YA-1 developed by Yamaha 1954, as basic road transport. YA-1, was the first motorcycle mixing systems lubricant and fuel in two-stroke engines. From the YA-1, He came the DT1, equipped with an engine 250 cc two-stroke.
Sales model year 1975 for the debut of the YZ250 not approach the immensely popular versions like the YZ125. Yamaha also produced 101.620 YZ125 motorcycle for 1975 compared to only 2.759 of YZ250. Versions 1975 They presented a yellow color scheme with “C” Checkerboard stripes in black and white. A belt held the fuel tank down, but Yamaha replaced it with a bolt-on style 1976. Production for the YZ250 models 1976 He jumped to 103.405.
All versions except the YZ80 YZ, They received the shock absorber system. Yamaha fuel tank is replaced with aluminum plastic version. In 1977, motorcycle manufacturer redesigned the chassis and engine combination. In 1982, the YZ125 and 250, They are receiving the first valve Yamaha power to increase production. YZ250 also converts air cooled to a liquid cooling system in 1982.
The version 2002 Yamaha YZ250 counted with a displacement of 249cc monocilíndrico, two-stroke engine, with a compression ratio of 8,8 a 1. Its diameter was 2,6 inches and the stroke measured 2,8 inches. The route of the front suspension was 11,8 inches, while the rear is 12,4 inches. The YZ250 mounted on a front wheel 21 inches and rear 19 inches. Stopping power comes from a single front disc brake 9,8 inches and rear disc 9,6 inches. It sat on a wheelbase 58.5 inches, measure 85,9 centimeters long and 51.3 inches high, and its frame cleared the ground for 15,4 centimeters. Its dry weight was on the sidewalk 215 pounds.
For the year 2003, YZ250 underwent a series of improvements. Yamaha modifies the rigidity of the frame and swingarm to reduce weight and improve management. To improve overall performance, Yamaha reformed exhaust ports of the cylinder, the crankshaft is made stiffer by increasing its tuning and changed the second transmission ratio. The weight of the bike was further reduced by redesigning the rear caliper, while simultaneously increasing the diameter of the piston to be stiffer. Yamaha also shaved 350 Fuel tank grams.
With the continuation of weight reduction measures since 2003 and adding the structure of lightweight aluminum in 2006, the YZ250 did not gain any weight despite numerous improvements in rigidity to the structure and components. Yamaha expands a component to ensure durability, makes up for the change of another component to keep the bike light. Engine compression ratio increased to 8,9 a 1 for better torque. Dimensions of the bike have been virtually unchanged since 2002.