Yamaha YZ490: history, specs, pictures

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1982-Yamaha-YZ490J-Yellow-0.jpg
Yamaha YZ490
Manufacturer
Production 82-90
Class Motorcross
Predecessor Yamaha YZ465
Engine
490
Top Speed 88 mph
Spark Plug NGK B9EG '82 , '83-85 , '86-87
NGK B8EG '88-90
Front Tire 3.00-21 '82
80/100-21 '86-87 , '88-90
100/90-21 '83-85
Rear Tire 140/80-18 '83-85
110/100-18 '88-90
140/90-18 '82
80/100-18 '86-87
Weight
Recommended Oil Yamalube 10w-40
Related Yamaha IT490
Manuals Service Manual


The Yamaha YZ490 is a motorcycle produced by Yamaha from 1982 to 1990.

Yamaha introduced the YZ 490 in 1982, after a solid run with the YZ465.

Problems[edit | edit source]

Sadly, the 490 was heavier than the 465, nowhere near as reliable, horribly difficult to start (hot or cold), came with a grim suspension, vibrated enough to bring blisters to your hands and was impossible to jet.

If you jetted it rich enough to keep this dog from seizing, it would blubber, puke, foul plugs and produce no power. If you jetted it to run strong, it would invariably seize. It came with air leaks, a wandering ignition, gimpy motor mounts and the worst case of Yamahop at high speeds since the original DT-1. Yamaha issued a mountain of service bulletins to try to fix the problems. None of them worked.


1982[edit | edit source]


1983[edit | edit source]



1984[edit | edit source]


1985[edit | edit source]


See Also[edit | edit source]


Yamaha YZ490
Manufacturer
Also called YZ 490
Production 1987
Class All
Engine
single cylinder, two-stroke
Top Speed 88 mph
Horsepower 53.77 HP (40.1 KW) @ 7000RPM
Fuel System carburetor
Transmission Gear box: 5-speed

Final Drive: chain

Clutch: wet plate
Brakes Front: single disc
Rear: expanding brake (drum brake)
Weight 235.89 pounds (107.0 Kg) (dry),
Recommended Oil Yamalube 10w-40
Manuals Service Manual


The Yamaha YZ490 was a single cylinder, two-stroke All motorcycle produced by Yamaha in 1987. Claimed horsepower was 53.77 HP (40.1 KW) @ 7000 RPM.

Engine[edit | edit source]

The engine was a air cooled single cylinder, two-stroke.

Drive[edit | edit source]

The bike has a 5-speed transmission. Power was moderated via the wet plate.

Chassis[edit | edit source]

Stopping was achieved via single disc in the front and a expanding brake (drum brake) in the rear. The bike weighed just 235.89 pounds (107.0 Kg).

In Media[edit | edit source]

References[edit | edit source]