do all 2003 Wr450F's need a starter upgrade?

I bought my WR450F after selling a KLR650 which was too top heavy and extremely difficult to lift up when I fell in the dirt.I like the idea of the DP bike. It really felt clumsey on the few cow trails I rode it on. I sold it and then looked at the DR400 had a deposit on one but the dealer jerked me around so I decided to go with the WR. I found one with very few miles (still has the new tire nubs from the mold) that had been traded in on a snowmobile in upper Utah. It's a 2003. I rode it once around the block decided it was too tall sent the rear shock out for shortening and lowered the forks about 1 1/2 after changing out the bars and bar bracket. I checked by the serial number and yes there is the punch mark meaning something had been done about the woodruff key. I've read on the forum that the 2003's have starter problems that are solved by using the 2004 parts. Gees I bought alot of parts and could put them on a 2004 and sell the 2003 if its really going to be a problem bike.I wanted to go out and explore dirt trails and hopefully do some of the continental divide. Can I get some opinions from you and suggestions. Should I sell it and move on to a more reliable year or fix the problems? If so will it ever be a stone reliable machine for long days on the trail? thank you. :naughty:

My 03 450 is fine with no mod, I just kept an eye on the flywheel torque for the first few miles, I did have to retorque my flywheel nut 3 times during the breaking period (this is what the manual say's to do). I would say you are fine if the factory mod was done. I also put 2 small punch marks on my crank and nut so I could quickly check the marks to see if they ever move. :naughty:

i would say YES. 100%

for the price of the parts, it is good insurance.

Did the upgrade, was $209 (through a place in NV I just told them I found it on the internet) and it took 15 minutes. Just do a search for the part numbers (or look on this url).

You DO NOT need the left side case, Just the bushing. I didn't even take the left side cover off, just tapped the bushing in with a piece of brass making sure its going in straight. Its cheap insurance but even more Peace of mind. I've done all the free mods and jd kit and the bike screamed on my 100 mile trip Friday.

The factory fix to the 2003WR starter gear train assy did not fix the basic problem with the design. When the motor backfires, the idler gear doesn't freewheel backwards. The force is exerted on the flywheel woodruff key which shears and you push your motorcycle back to the truck. The factory fix increased the torque on the flywheel nut and Loctite was applied to the flywheel nut. When the motor backfired, you stripped the starter gear or cracked the side case. You still pushed the motorcycle back to the truck. The 2004 WR changed the starter idler gear to a design that free wheels backwards when the motor backfires. There have been no problems with this design. Do a search under BajaFool for a list of parts, prices, source for purchase and installation instructions. Yes, the fix is a little pricey (its late at night here and I don't remember exactly --- couple hundred dollars maybe) and takes 10 minutes. It is worth every penny of the cost for peace of mind.

I bought my 03 new with a dealer performed flywheel mod. Being paranoid I pulled all the covers to check and see if the idler gear freewheels backwards, it does. I checked with a guy who did the 04 update and I definitely don't have the 04 parts in my bike. But since the idler freewheels nicely I skipped the starter update and have 7000 trouble-free miles. Its backfired many times, when starting and especially when sorting out the jetting for altitude changes. Makes me think there are possibly some VIN numbers in 03 that wouldn't freewheel and some that would. FWIW.

yamaha was in a big rush to get the WR450 ready for the 2003 market. and it shows!!!

they also forgot the 6th gear..................

I have the very first 2003 WR 450 on ThumperTalk. I got it January 9, 2003.

I have done nothing to the flywheel/woodruff key. I have never had a problem. I doubt if I have the punch mark, I've never looked. Since I had the first one I doubt that the flywheel/woodruff key problem was even addressed. It has never been back to the dealer.


Since the starter motor spins freely both directions unless you have the button pushed then the only time a backfire should be able to shear the key is during starting. I have always been carefull to not just hold the button in and crank endlesly.

You can get all the parts needed at for $175 shipped. I just did the upgrade last week simply for piece of mind even though I have never had a problem at 4000 miles. $175 is cheap for piece of mind.


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