Yamaha YZ490: history, specs, pictures
|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
|Rear Tire||140/80-18 '83-85
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.
|Also called||YZ 490|
single cylinder, two-stroke
|Horsepower||53.77 HP (40.1 KW) @ 7000RPM|
|Transmission||Gear box: 5-speed
Final Drive: chain
|Brakes||Front: single disc
Rear: expanding brake (drum brake)
|Weight||235.89 pounds (107.0 Kg) (dry),|
The engine was a air cooled single cylinder, two-stroke.
The bike has a 5-speed transmission. Power was moderated via the wet plate.
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).