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I've been tossing around the idea of selling one of the motards and thought maybe get rid of the 2000 YZ426 and make the 04 WR450 my race bike. These 2 bikes have very different gear ratios and i was curious to see if the WR would work as good as the YZ at the track?
Here's the YZ specs...
1st 24/13 (1.846)
2nd 27/18 (1.500)
3rd 23/18 (1.278)
4th 24/22 (1.091)
5th 20/21 (0.952)
Now the WR specs
1st 29/12 (2.416)
2nd 26/15 (1.733)
3rd 21/16 (1.312)
4th 21/20 (1.050)
5th 21/25 (0.840)
Seems like the biggest difference is in first and second on both bikes and the rest are reasonably close. Any thoughts on the advantages and disadvantages of each one?
I'm guessing the lower first gear would make for beter starts but is there to much of a drop after that?
I'm not going to make any changes befor this weekend but "if" i do something, i'd probably have it ready for the June race weekend.
Thanks for any help
Yamaha
The WR will be more wheelie prone with the taller ratios, but will have longer legs in top gear...This also depends on what the 2 bikes have for a final drive ratio...front sprocket and rear sprocket.
If the WR has a numerically lower final drive ratio, it may translate as not so wheelie prone, but will have a higher top end over the YZ, if it can make the power over the YZ.
The WR probably makes close to the same amount of power as the YZ, the WR is 450cc and the YZ is 426cc.
As for the final drive, now i have 15/40 on the YZ and 14/38 on the WR. I have 12,13,14,15, and 16 tooth countershafts so i can adjust accordingly
Yamaha
The final drive ratio on the WR is 2.714 to 1
While the final ratio on the YZ is 2.666 to 1.
They are both equally close..... so what this shows if you kept the ratio as it is with the WR, it'll have more grunt outta the hole and a little less RPM's or more top speed on top if it has the HP to pull top gear to redline.
Thanks for the help Mark![]()
It looks like some small mods will have to be done to get the WR motor up to YZ performance specs, most of which i have done already. Some carb jetting and a YZ exhaust cam "should" make as much power as the YZ450FThe WR is a little bit heavier than the YZ as well but i could trim the fat by removing the battery and electric starter, and some other small odds and ends.
We'll see, something i have to think about i guess. As fun as the WR is to ride around on the streets, everywhere i go with it i get stopped because it doesn't "look" street legal![]()
Yamaha
Go figure huh?Originally posted by R7
We'll see, something i have to think about i guess. As fun as the WR is to ride around on the streets, everywhere i go with it i get stopped because it doesn't "look" street legal![]()
After you get the camshaft in and set up, it would probably be wise to get up there on a thursday, and fool with some final sprocket ratios....
Just have someone get some lap times on you, and you can compare results.
Mark, I've run as tall as 15/37 on my 400,and it still runs out before turn one.I think the taller gears in the WR would be an advantage.If I hadn't already spent a million bucks on mine, I would put 4th and 5th out of a WR in there.