2003 WR450, Need help on dialing in this wart hog!

I just purchased this bike and live in Calif. at about 2500'elevation and was wondering what you think the right jetting would be,plus turns out on the air-fuel screw?The bike is stock exept for a white brothers E-series pipe,how many discs should i use on the pipe? ,grey wire cut,air box mod,it has a punch mark on the serial no.does this mean im OK?Any input would be great! Thanks. :thumbsup:

Jetting should be 160 main, stock clip #5, 45 pilot 2 turns on the screw. Serial number does not mean much. Just check for 04 starte upgrade or woodruff key repair history. :thumbsup:

The punch mark means they did the recall fix, but thats not good enough. You have to purchase the starter gear for an 04 You can tell if its already been done the starter gear cover on the 03 is flat the cover on the 04 swells out about a 1/4/ inch. Its easy to do youself it takes all of about five minutes and yes its worth it. I'd use eight discs, its pretty quiet and gives you more bottom end.

YAMAHARICHEY Do you have the new side cover and gear installed in your 03, I didn't see it listed in your bikes extra's.. Big Jim :thumbsup:

Thanks,can you tell me what you paid for parts for the starter mod?

You can save $100.by not getting the left side cover by ordering the bushing and pressing it into the existing cover and also do not need the gasket. The bushing is part number 90380-10002 (cost $0.96)

The parts needed:

04 Left Side Case Part # 5TJ-15411-10-00 @ $ 92.49

04 Torque Limiter Part # 5TJ-15560-00-00 @ $204.99

04 Torque Limiter Cover Part # 5TJ-1549B-00-00 @ $28.99

04 Thrust washers (need 2) Part# 90201-105A8-00 @ $ 7.98

Gasket for side cover Part # 5TJ-15451-00-00 @ $ 4.49

see detailed instructions with pics at: www.wr450.com

So what happens if i dont do this mod? :thumbsup:


Maybe you will shear the flywheel key and then again maybe you won't. I have the very first 2003 WR 450f of all of the Thumpertalk brothers and I lost a fork seal, and that is the only problem. Other members have replaced the flywheel key as many as 3 times. It is kind of a crap shoot. Some of the bikes have had NO problems and others have been broke down more than they have been ridden. There seems to be no rhyme or reason as far as I know. As I have said mine is the first and I've gotten over 1800 miles on my bike, others have far more miles with no throubles and then there are guys like Jeff in Eugene who has had three keys shear and finally Yamaha replaced the crank and all related parts and I guess that his problems are solved as I haven't seen any more posts from him on the subject.(He had a lot less miles when it went the first time) I hope that this helps to answer the question.


It will break eventually. Mine never did but I upgraded when I heard of guys breaking the key a year after getting the bike. Some cases the engine case had split so the damage can be real bad if the key doesnt break. It just makes sense to spend $260. and not worry about breaking down in the middle of nowhere. :thumbsup:

Thanks for the input guys,What about the rest of my questions?Jetting? :thumbsup:

160 main, Stock Needle clip 4 or 5, 45 pilot. :thumbsup:


How can you say it will break eventually? There are a lot more of these '03's out there that have had no problems than have. I personally have over 2600 miles with no problem at all. You claim to have ridden over 5000 miles before doing the "upgrade" with no problems. Most guys will never put 5000 miles on these bikes in 5 years. Throwing down $260 for a fix that has not been proven to be needed is a waste in my opinion.

Not trying to call you out but wanted to let it be known that it's not a death sentence to have not done this mod.


Watch, Mine will probably break now :thumbsup:

You say IT will happen,OK,what will happen? And why didnt Yamaha re-call this? :thumbsup:

Click here for more info. "It" is the woodruff key that we are refering to. Yamaha had a technical service bulletin to their dealers to try to prevent the sheared key. The punch mark on your bike tells you the TSB was performed.

As far as jetting goes, I would recommend buying the JD jetting kit through the TT store. It is well worth the $60.


Throwing down $260 for a fix that has not been proven to be needed is a waste in my opinion.

If a person has had the Yamaha TSB done on his bike then this upgrade is absolutely necessary, IMO. There have been instances where it doesn't break like it should (due to the flywheel being loctited to the crank from the TSB) and something else breaks instead (starter, starter gears, cases.) The starter update resolves this issue with the torque limiter that is the main part of the 04 upgrade.

I haven't had the TSB done on my bike and it lost a woodruff key at just over 2,600 miles. With as many miles as I put on in the back country, $260 is cheap peace of mind. :thumbsup:

Yes, I still pack a flywheel puller, two spare woodruff keys (and all the tools necessary to fix it on the trail) in my fanny pack. :awww:

Hey Lowedog. I was of the opinon that with proper jetting that the woodruf key failure would not happen. But after seeing Yamaha take the time to redesign around the issue in 04's you have to think that something is up. Yamaha could have just loctited all the 04's at the factory and called it done. Instead they came up with the weirdest concotion of a torque limiter that I have ever seen just so it can fit in the existing engine design. They would not have done this unless they had a design flaw in the 03 starter drive train. I just feel that it is a matter of time before they all fail. maybe it is 2 or 3 years for some. Maybe 10,000 miles. But eventually the dice will roll a failure with the design flaw. :thumbsup:

I did a reply on this a couple of hours ago but for some reason it doesn't show. So I'll say it again. When I bought the starter parts from my dealer, I told him I didn't think he should make a profit on those parts because this is Yamaha's fault, He's a great guy and agreed with me The total I paid was $150.00. Remember you don't need side cover and gasket.

Dave, Didn't you say that the flywheel nut may have not been torqued to the proper spec or that it may have backed off some at the time that yours failed? It is probably something to check regularly on the '03's that have not had the '04 mod. I put a couple of marks on the torque limeter on my bike and check it once in awhile and have found the marks to move away from each other. Does the '04 torque limeter move freely in the opposite direction of starting?

As far as the loctite goes was it the flywheel taper to the crankshaft taper that was being loctited or the nut on the flywheel? I can't see there being enough loctite left between the tapers to cause enough holding force to not shear in the case of a bad torque limeter. I wonder if the bikes that have broken in other areas have been caused by the TSB being performed incorrectly? I also know that the YZ 450's have had problems with the case breaking around the kickstarter. I wonder if Yamaha didn't throw this engine into production a little early.

Does the new torque limeter look like it warrants the high price they are wanting for it?

I guess $260 isn't too outrages for a little peace of mind. A freind of mine pulled his starter because he was worried about it. He did have some backfire/ stalling issues. He found a few teeth missing on the starter. I figured he had a bad torque limeter.

The dealer supposedly did the TSB on mine when I bought it but they didn't punch the frame.

I just have a hard time plopping down the $260 to fix something I have never had a problem with. (sounds like I'm trying to talk myself into it :thumbsup:)

:awww: Lowedog

BTW Dave, I have a sprocket guard for you buddy with the YZ 250F. :lol:

Yamaharichey, That is a great idea. Unfortunatly not all dealerships feel that way. I hit my dealership up with that awhile back and was told that they wouldn't even consider it if I had never had a problem.



Damm it!! I should have done my homework before buying this bike! Any body want to buy a clean wr450?(500miles)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now