Bearing part numbers

I recently purchased an 03 450F and I am very happy with it. While tearing it down to check all the bearings, I discovered the front wheel bearings are shot and I can't seem to find any part numbers to replace them. I am not buying the replacement bearings from a dealership and was wondering if anyone knew the bearing numbers.



Any time i've needed bearings for my bikes, I try and take a sample (even a damaged one, if that's all you have) to a bearing supplier. They can usually measure it up, and match it to something on their books. You should be fine with wheel bearings, but certain m/cycle bearings can only be sourced from the specific manufacturer. A bearing wholesaler is way cheaper than genuine parts too :cry:

BTW, if you ring up and tell them the width of the outer bearing shell, and the inner (axle) diameter, they should be able to tell you over the phone if they can match it. I've never had to buy genuine when it comes to wheel bearings.....

There should be a part number on the race as well as a part number on the dust seal. I replaced mine some time back and just ordered a wheel bearing kit from Bobs Cycle, but many on line places carry them.

Just went through this with 2 sets of stock bearings on my 03 450 - now i ordered Pivotworks - 25.00

the Stock bearings I believe are crappy -

I got two full race seasons from my stock bearings, so I can't complain. Pivot works are what I purchased as well.

Got to agree Pivot Works are some good bearings. I order mine from Rock Mountain MC. Be sure to grease the new ones up with some waterproof grease I have used the Belray grease and it seems to do pretty good. The Silkolene is to thin and will break down pretty quick in my experience

Okay, this is really simple to decode from the Yamaha part numbers.

First get the Yamaha part numbers:

93306-90403-00 BEARING in your case for the front wheel bearing on the YZ450 2003.

Now see the 5th thru 8th digit? IN this case 6904. Go to any autoparts or bearing supply store and ask for a 6904 bearing with rubber seals on both sides. The 6904 is the bearing size. They are WAY cheaper than anything you can purchase at a bike shop. Most bike shops have bulk bearings also, so you may be able to get the 6904 bearings at your bike shop.

now when you get the new bearings, you will need to gently pry up the rubber seals on the bearings to remove them. Then pack the bearing with quality waterproof grease and reinstall the seals and then install the bearings.

Mine was a Koyo 6904. I tried NAPA, AutoZone, and Advanced Auto parts. All of them told me they did not carry that bearing. A bearing supply house told me they could get the bearing, but not the seal. I wanted to go that route as well.

most places can get them overnite from distributors. You just have to ask.

Thanks for all the help guys. I think this should get me going


I got mine from here. The bearing are SEALED!!!!!. I received them in about a week. So far, so good. :cry::cry: See link below;

Sealed Bearings

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