Another starter question.

Hi all. My wife just bought me a 2003 plated WR450 for Christmas. The battery is shot and won't hold a charge but it starts right up with a couple of kicks. Went for a couple hour ride Christmas day and my only complaint was a bad mid range flat spot. After searching this forum, it sounds like it is more than likely a partially clogged jet. I also noticed on this forum that the 03 has starter problems, so before putting in a new battery and pushing the button I wanted to fix the problem. Before buying parts I would like too know if this has already been done, the guy I got it from has no idea. How can I tell if this has already been done?

Before buying parts I would like too know if this has already been done, the guy I got it from has no idea. How can I tell if this has already been done?

If your '03 has has ALL the starter drive updates, the small round cover (with two bolts, on the mag cover), will have a 'bulged' apearance. The original cover was nearly flat. If you pull the cover and look inside, the piece inside will have what appears to be a little clutch inside. The original is a simple gear with a shaft.

Does your starter make ugly noises when you are cranking?

If your '03 has has ALL the starter drive updates, the small round cover (with two bolts, on the mag cover), will have a 'bulged' apearance. The original cover was nearly flat. If you pull the cover and look inside, the piece inside will have what appears to be a little clutch inside. The original is a simple gear with a shaft.

Thanks Jim, That's exactly what I wanted to know. Mine is stil stock. :bonk:

Does your starter make ugly noises when you

I have not tried starting it with the starter yet. The guy I got it from said he tried using the starter when he first bought it and it would just spin. Where is the dreaded woodruff key located?

I have not tried starting it with the starter yet. The guy I got it from said he tried using the starter when he first bought it and it would just spin.

It probably hasn't had the upgrades (post a closeup pic of the starter drive cover if you can). It also sounds like the starter sprag on the inside of the flywheel is toast.

Where is the dreaded woodruff key located?

You are confusing the starter problem with something completely different.

'03 WR's didn't have the flywheel properly torqued from the factory and they would shear the woodruff key that located the flywheel to the crankshaft. When this happens, the bike won't start or run. There will be spark at the plug but the timing will be off far enough that it won't run.

It probably hasn't had the upgrades (post a closeup pic of the starter drive cover if you can). It also sounds like the starter sprag on the inside of the flywheel is toast.

WR450?authkey=Gv1sRgCNyN4ae3hqasew#5691651647392957138

#~loop:pid=4270255592832652140&alid=5691651629139965873&phid=5691651647392957138&view=photo

#~loop:pid=4270255592832652140&alid=5691651629139965873&phid=5691651665172560930&view=photo

You are confusing the starter problem with something completely different.

'03 WR's didn't have the flywheel properly torqued from the factory and they would shear the woodruff key that located the flywheel to the crankshaft. When this happens, the bike won't start or run. There will be spark at the plug but the timing will be off far enough that it won't run.

Gotcha. Is it usually sheared from a backfire while using the electric starter?

Edited by signman1968

Pics didn't post. Can't see them.

I think the culprit for the key shearing is when you bump started the machine, that was the only common factor I ever saw.

'03 WR's didn't have the flywheel properly torqued from the factory and they would shear the woodruff key that located the flywheel to the crankshaft.
Proper torque isn't and never was the problem with the woodruff key. Yamaha made lame excuses for their poor design in '03, but upgraded the problem part in '04. The issue is idler gear 1 (5TJ-15512-01-00, under the flat cover). It does not freewheel backward if the engine backfires while e-starting which would often shear the woodruff key. The part was upgraded in '04 to a damper assy. (5TJ-15560-01-00) which will protect the woodruff key if it backfires while e-starting. It's a drop-in upgrade, IIRC, only requiring the damper assy, two plate washers (90201-105A8-00) and cover assy 2 (5TJ-1459B-00-00) :bonk:
Proper torque isn't and never was the problem with the woodruff key.

Hmmmm.... That's funny, all of the '03 WR's I did the service bulletin work on never had the problem again. Including my own '03 (which I still ride).

Yamaha made lame excuses for their poor design in '03, but upgraded the problem part in '04.

Agreed. It was a poor design but had nothing to do with the woodruff key shearing issue. The flywheel and crank were redesigned in '04 in addition to the torque limiter device update. There were several reasons for this. The primary one was to eliminate the needle bearing and thrust washer that the starter gear rode on behind the flywheel. The reason for the change was to prolong the life of the one-way assembly (5TJ-15590-00-00).

Not trying to apologize for the bad design but the key shearing and the starter drive issues were two distinct problems not related to each other.

The issue is idler gear 1 (5TJ-15512-01-00, under the flat cover). It does not freewheel backward if the engine backfires while e-starting which would often shear the woodruff key. The part was upgraded in '04 to a damper assy. (5TJ-15560-01-00) which will protect the woodruff key if it backfires while e-starting. It's a drop-in upgrade, IIRC, only requiring the damper assy, two plate washers (90201-105A8-00) and cover assy 2 (5TJ-1459B-00-00)

The starter drive changers were done for one reason only; prolong the life of the starter drive parts, primarily the one-way assembly. When the one-way assembly became damaged, it would have the teltale 'grinding gears' inside the mag cover when the e-starter was engaged. This was caused by rapid slipping-grabbing-slipping of the one-way assembly. The hammering would cause the six retaining bolts to loosen and destroy the stator and flywheel. The torque limiter prevents the violent chattering in the one-way assembly that can damage it.

You have to give Yamaha credit for doing warranty repairs on WR's with the sheared woodruff keys long after the warranty had expired in most cases, something Honda refused to do with the horibly designed valvetrain on the '02-'08 CRF450R.

Not trying to apologize for the bad design but the key shearing and the starter drive issues were two distinct problems not related to each other.
Out of hundreds of woodruff key posts, you're the first one to say that they aren't related and that lapping and increasing torque wasn't a poor bandaid fix. You know there were more woodruff key failures after the service bulletins were performed, but the damage was worse, including broken gears and cases. There were no sheared keys on '04+ WR's or on '03's with the '04 upgrade :bonk: I didn't shear my key, did the '04 upgrade anyway and then put 10k miles on my bike without shearing it :smirk:
Out of hundreds of woodruff key posts, you're the first one to say that they aren't related and that lapping and increasing torque wasn't a poor bandaid fix. You know there were more woodruff key failures after the service bulletins were performed, but the damage was worse, including broken gears and cases. There were no sheared keys on '04+ WR's or on '03's with the '04 upgrade :bonk: I didn't shear my key, did the '04 upgrade anyway and then put 10k miles on my bike without shearing it :smirk:

All I know is what I experienced fisthand as a Yamaha tech. On machines that were brought to the dealer with a sheared key, I never had to do anything other than remove, clean and reinstall the flywheel with a new key and torque to the new spec (and never charged the customer for the repair). Of all the machines I did this work on, none of them returned for the same problem and none of them had the '04 upgrade parts. I did see quite a few one-way assembly failures and that was usually the impetus for the owner to spend the money on the upgraded '04 starter drive parts but this was over a year after the woodruff key issue surfaced.

On my personal '03 WR450 (which I purchased new), I performed the retorque before riding it the first time and in 7 years of riding, never sheared a key. I did replace the starter drive parts two years after I purchased the bike for no other reason than the horible grinding sound when the e-start was engaged.

Again, I will give Yamaha credit for recognizing the problem, quickly making necessary design changes, and taking care of their customers. When you consider the horrible Honda '02-'08 CRF450 valve life issues because of the under-sized cam bearings and the ridiculous use of four 6mm bolts to attach the entire valve train to the head, and Honda's steadfast refusal to acknowledge a problem, I just don't consider the key shearing or starter issues to be a big deal.

I've tried uploading the pictures from two different sites with no luck (wish you could upload straight from the computer). All teeth on all gears are in good condition and show no signs of grinding. I did hook up the battery and try the starter before putting the gear and mag cover back in place, and yes the starter squeeled horibly. And it deffinately has not had the updates done yet.

I've tried uploading the pictures from two different sites with no luck (wish you could upload straight from the computer). All teeth on all gears are in good condition and show no signs of grinding. I did hook up the battery and try the starter before putting the gear and mag cover back in place, and yes the starter squeeled horibly. And it deffinately has not had the updates done yet.

It's hard to say for sure, but from what you described, it sounds like the statrer motor itself needs to be rebuilt or replaced.

Try using photobucket.com

After you have uploaded your pics to photobucket, the saved images will have a small box under them that says 'IMG code'. Right click on the code to highlight it and copy-paste to the body of ypur post. The image code will be bracketed on either side with the letters IMG.

66C8855D-orig.jpg

067BCE65-orig.jpg

Very nice. No, you don't have the updated pieces.

Thanks again Jim.

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