Yamaha YZ125: review, history, specs

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Yamaha-yz125-2007-2007-1.jpg
Yamaha YZ125
Manufacturer
Also called YZ125X, YZ 125
Production 1997 - 2019
Class Motocross
Engine
single cylinder, two-stroke
Bore / Stroke 54.0mm x 54.5mm
Compression ratio 10.7:1
Top Speed 72 mph
Torque 17.7 ft/lbs (24.0 Nm) @ 10000RPM
Ignition cdi
Spark Plug NGK B10EG '76-80 , '81
NGK B9EG '74-75
NGK B9EG '82 , '84-85 , '88-98
NGK BR9EG '83 , '86-87 , '99-08
Transmission Gear box: 6-speed

Final Drive: chain

Clutch: multiplate wet clutch
Suspension Front: kyb® speed-sensitive system inverted fork; fully adjustable
Rear: kyb® single shock; fully adjustable
Brakes Front: single disc. hydraulic.
Rear: single disc. hydraulic.
Front Tire 3.00-21 '76 , '77-80 , '81 , '82
2.75-21 '74-75
80/100-21 '86-87 , '88 , '89-93 , '94-96 , '97-98 , '99-04 , '05-08
90/90-21 '83 , '84 , '85
Rear Tire 6675 '76 , '77-80 , '81 , '82
130/80-18 '83 , '84 , '85
100/90-19 '89-93 , '94-96 , '97-98 , '99-04 , '05-08
3.50-18 '74-75
100/100-18 '86-87 , '88
Wheelbase 56.81 inches (1443 mm)
Length 84.09 inches (2136 mm)
Width 32.6 inches (828 mm)
Height 50.98 inches (1295 mm)
Seat Height 38.39 inches (975 mm)
Weight 190.04 pounds (86.2 Kg) (dry), 93.9 kg (wet)
Recommended Oil Yamalube 10w-40
Fuel Capacity 2.11 Gallon (8.00 Liters)
Related Yamaha YZ50
Yamaha YZ60
Yamaha YZ80
Yamaha YZ85
Yamaha YZ100
Yamaha YZ125
Yamaha YZ250
Yamaha YZ400
Yamaha YZ465
Yamaha YZ490
Competition Honda CR125R
Kawasaki KX125
Suzuki RM125
Manuals Service Manual

Brochures ·


The Yamaha YZ125 was a single cylinder, two-stroke Trial motorcycle produced by Yamaha between 1997 and 2019. Max torque was 17.7 ft/lbs (24.0 Nm) @ 10000 RPM.

Engine[edit | edit source]

The engine was a liquid cooled single cylinder, two-stroke. A 54.0mm bore x 54.5mm stroke result in a displacement of just 125.0 cubic centimeters.

Drive[edit | edit source]

The bike has a 6-speed transmission. Power was moderated via the multiplate wet clutch.

Chassis[edit | edit source]

It came with a 80/100-21 front tire and a 100/90-19 rear tire. Stopping was achieved via single disc. hydraulic. in the front and a single disc. hydraulic. in the rear. The front suspension was a kyb® speed-sensitive system inverted fork; fully adjustable while the rear was equipped with a kyb® single shock; fully adjustable. The YZ125 was fitted with a 2.11 Gallon (8.00 Liters) fuel tank. The bike weighed just 190.04 pounds (86.2 Kg). The wheelbase was 56.81 inches (1443 mm) long.

First Generation[edit | edit source]

1974 YZ125A[edit | edit source]


  • SERIAL # 453-000101 - 007730

1976 YZ125C[edit | edit source]

1975[edit | edit source]

  • SERIAL # 453-100101 - 101620

1976[edit | edit source]

  • SERIAL # 537-000101 - 014044

1977[edit | edit source]

  • SERIAL # 1W1-000101 - 015610

1978[edit | edit source]

  • SERIAL # 2K6-000101 - 015080

1979[edit | edit source]

1979 Yamaha YZ125
1979 Yamaha YZ125
1979 Yamaha YZ125
1979 Yamaha YZ125