CB key replacement, and 03' 450?

Just replaced the CB key. I did a search on this site and got some great info on how to change. Not to bad of a job. If I only have to do this once a year, not bad. One thing I would suggest is if you do not have a clutch tool, get one before the change.. Just read in MX action mag. that for 03' the YZ was going to be a 450? anyone have any better info on this. If this is so and they shed some wieght, I may have to take the plunge and get one.. Thanks to all those who posted help for the CB key change.

I heard the WR version of the '03 450 may in fact have a magic button! Yamaha will be able to take a lot of business from KTM and the others who have 4 strokers with electric starts. I also heard the Honda '03 model will NOT have the magic button.

Hey 426Fireman,

You and me were doing the same thing this afternoon I guess. I ordered a new CB key this week and picked it up this afternoon. I put the new key in and checked the drive gear for play before putting the nut back on and damn if it did not still look to have the same problem of not really being a tight fit.

Well, I have read some threads about other guys making their own keys, so I went to the hardware store to get one that was a little bigger and longer. I spent about an hour carefully filing the new key down to size and tapped it into the notch on the crank. After I lightly tapped the drive gear into place on the crank it now seems to be tight with no side to side play at all.

I am very anxious to find out how it turns out tomorrow when I finish putting the whole thing back together. I really hope this solves the problem, I have been trying to fix this engine noise for over a year now.

Oh yea, I found an interesting way to hold the clutch inner basket with a large C-clamp. I don't recommend it to be duplicated, but it worked this time in a pinch. I really need to get a clutch hub holder for my tool box.

NOpremix, I did not even try the factory key, i did the same as you, went and got a 1/4" by 1" key and filed it to a perfect fit. Hope this works for this year. Don't mide doing this in the off season, but hope not to have to do it again till after the fall ride at the end of Oct. Thanks for the comment, I love my 426. That is interesting to see the magic button on the 03' wr450. This will sell alot of wr's.

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