1983 Yamaha YZ490
Before Ricky Carmichael entered the motocross scene, Broc Glover was a record-holding motocross racer. He won six AMA National Motocross Championships over the 1970s and 1980s, one being the 1983 500cc championship, on a 1983 Yamaha YZ490.
The 1983 Yamaha YZ490 was a great big bore two-stroke that really lit up when you hit the top-end. The engine was a bit sluggish in the bottom end, but excelled in the higher RPMs. This made the YZ490 great for longer tracks and hare scrambles. As fast as the 1983 YZ490 was, though, the brakes didn’t always seem to match up. The back brake was good, but the front brake was decent at best. They got the job done, but probably not as easily as most would like.
The 83 YZ490 had the typical Yamaha build. It was a longer bike with low bars. Like many big bore bikes, the kickstarter was high and long, so many people had trouble getting the bike started.
As far as suspension, the 1983 YZ490 had an adjustable rear mono-shock, and 43mm KYB front forks with air valves for adding or releasing pressure. While the suspension system worked well for lighter riders, it was set up a little on the soft side for heavier riders. The handling of this bike was pretty solid, but many riders of the 1983 YZ490 raised the forks all the way up in the triple clamp altering the front end ergonomics, helping the to turn a little better and become more agile. While it handled very well and blew away the competition in the straights, it was harder to control in turns.
3 Comments
The 1983 YZ490 was one of the big three after Maico’s title of meanest 500 MX bike around. The GP490 and the Alfa 1 490 are considered by a lot of people to be the best MX bike around. The YZ490 was Yamaha’s answer to that. The rear suspension was Yamaha’s second generation of the original mono x. For a big rider the yellow rocket was a little soft. The rebound of the shock tends to wanna let the bike hop if you hit a square edge just right. Many an unfortunate rider experienced free riding lessons due to mono hop.
The KYB air forks were some of the best stuff around at the time. The 490cc air cooled motor likes to blubber a little in the lower rpm range but picks up power quickly. Once you really get them revving the 490 is amazing and pulls hard. With the right port and head work the engine can be made to run well down low.
Riding one of these power monsters is not for the novice. They ride a bit different than other machines. The front end tends to want to push in hard corners. Using the power to bring the rear tire around proves to be the best way to ride one. All and all it seems the 490 YZ was a step in the wrong direction from the YZ465. Yamaha never really did get this one right but the YZ465 was one of the best MX bikes Yamaha ever built.
@Austin: Use a YZ 490.
I need a motor, or what will fit in a 490 IT?