Yamaha YZ250

YZ250

Manufacturer	Yamaha
Production	1974-
Successor	Yamaha YZ450
Class	Motocross
Engine	250 cc single-cylinder, water-cooled, two-stroke, case reed
Power	49 hp
Torque	32 ft·lbf
Transmission	5-speed
Suspension	Monoshock, 12.8 inches travel
Brakes	double disc
Tires	Front: 80/100-21-51M ; Rear: 110/90-19-62M
Wheelbase	57.8 inches
Dimensions	L 85 inches W 32.5 inches H 51.2 inches
Seat height	39.1 inches
Weight	212 lb (96 kg) (dry)
Fuel capacity	2.1 US gallons
Related	Yamaha YZ450F

The Yamaha YZ250 is a two-stroke motocross race bike made by Yamaha. It was launched in the 1970s, and has been regularly updated since

Engine

The YZ250 has a 249 cc liquid-cooled two-stroke reed-valved engine with a YPVS exhaust valve for a wider spread of power. The engine produces a peak 48.8 horsepower (36.4 kW) at 8,800 rpm and 30.6 foot-pounds force (41.5 N·m) of torque at 7,500 rpm, with a 9,000 rpm redline (Motocross Action Magazine).

Chassis

Since its introduction in 1974, the YZ250 has had a single backbone steel frame. For the 2005 model year, however, the YZ250 has a new frame made entirely from aluminum, which brought the dry weight down to 212 lb (96 kg), and more recently in 2010, to 211 lb. The bike has a Swingarm rear suspension system with more than a foot of travel, as well as telescopic inverted forks with 11.8 inches (300 mm) of travel. Front and rear hydraulic disc brakes round out the YZ.

Championships

The YZ250 holds many championships:

• 5 AMA National Motocross Titles.
• 9 AMA National Supercross Titles
• Most recently, Chad Reed rode the YZ250 to an AMA National Supercross title in 2004.

See also

• YZ85
• YZ125
• YZ250F