The misunderstood YZ490

[PETE24]

love to throw out my restored 490 it was quite a project

 

[USED YZ426F]

Big bore smoker porn.......... ?

I often times wish I had kept my '89 YZ490.  It wasn't as nice as your bike, but it was a lot of fun to ride.

[sjsingle1]

love to throw out my restored 490 it was quite a project

 

OMG.......thats mine........as soon as i  get some more $$$$$$$$$

 

i am ashamed of how much $$$ i have sunk in it already ......and tracking down obsolete parts is a freakin PITA !!!!

 

you can still get those caps for the holes in the swingarm BTW.....

Edited February 10, 2014 by sjsingle1

[Red Mountain Addict]

Big bore smoker porn.......... ?

I often times wish I had kept my '89 YZ490.  It wasn't as nice as your bike, but it was a lot of fun to ride.

Realize this is a pretty old thread, but I'm trying to figure out a mystery here on an 89YZ250 I own that happens to have a Olin 360cc kit.  I was told by many people (mechanics mostly) that in 89, Yamaha didn't offer a YZ490 so many took the YZ250 and upgraded it with bore kits to race open class.  But I see many every where such as yourself mention an 89' YZ490.  I'm just trying to figure out what the deal was with YZ490's and the actual last year they were made.

 

[USED YZ426F]

The last year for the YZ490 was 1990.  After that, Yamaha made the WR500 for a few years which was basically a YZ490 engine stuffed into a YZ250 frame.  The last year for the WR500 was 1993.  Yamaha has not sold a big bore smoker in the US since then.

[YZScott]

Beautiful, bad ass, mo'effin build! great job. She is soooooo purrddddyyy! 

[YZScott]

I believe it's 4

One, two, three, and Sybian

 

? ? ?

[bigjt3]

That's why i just bought an 84 490, so freaking badass!

 

[Gibbit]

My current project.

Edited January 15, 2015 by Gibbit

[todintexas]

That'll be a nice one, pretty clean already. My "just finished" project... well, close anyway, they are never "finished". LOL

[Gibbit]

Nice work.

The mixture of red, white and yellow certainly make it look unique.

[todintexas]

Thanks GIBBIT, the theme was actually stolen from a Euro bike of the same era that I saw online. The tank is supposed to have yellow/red decals, haven't gotten around to that.

[ben williams]

I still love my 85 that spent to much money on. But I now have a green sticker bike. 

[vic2340]

I think the reason big bore two strokes are bad is because as you go up in cc you go down in rpm rev range. You get alot of torque and explosive power in a short amount of time. As a result you get more wheel spin and less traction. I believe anything over 300cc for a two stroke is an over kill for any situation. Sure big bores can be fun and unique but when the going gets rough they turn into medieval torture devises. If you like that kind of stuff hats off to you, keep it going. I will stay on my 250 two stroke and continue realizing how I would be better off on a 200 cc lol. Thanks for posting, all the best.

[arnego2]

I think the reason big bore two strokes are bad is because as you go up in cc you go down in rpm rev range. You get alot of torque and explosive power in a short amount of time. As a result you get more wheel spin and less traction. I believe anything over 300cc for a two stroke is an over kill for any situation. Sure big bores can be fun and unique but when the going gets rough they turn into medieval torture devises. If you like that kind of stuff hats off to you, keep it going. I will stay on my 250 two stroke and continue realizing how I would be better off on a 200 cc lol. Thanks for posting, all the best.

 

 

I think with a wider gear box and a tamer sprocket and rear it would be similar to a smaller bore.

[AzThumperRider]

I've had them all,yz490's 84 86 89 and I love them all. I also have the 87 cr500 and a 93 kx500. My Yz's vibrate and are loud have crappy brakes but when I hit the trails I always have a fun ride. 

[oldman]

My recently finished 82 YZ490 project.

There are many who say the 82 YZ490 could not be made to run clean without pinging.   With the proper head modification and jetting changes it runs clean, strong and crisp as a good tuned 2 stroke should.  Point in the direction you want to go and "Hang On" you will be arriving there in a short amount of time!!

Edited November 5, 2019 by oldman

[GCannon]

Isn't that a 4 speed trans in that 82? Very Nice!

I miss my 81

[oldman]

On 11/5/2019 at 11:01 AM, GCannon said:

Isn't that a 4 speed trans in that 82? Very Nice!

I miss my 81

Yes, the 82 is a 4 speed.

[john stu]

On 11/15/2008 at 4:36 AM, Drinky Chinky said:

With a good tune up, stock for stock a yz 490 will hang right with a kx or cr in a staright line. With a lil port work and a good head job and carb work the kx and cr will never touch it, not on accleration.

Lol ya ok