WR450 2003 and noisy engine

37 replies to this topic
  • Kossu

Posted June 08, 2004 - 12:58 PM


Is the primary gear nut directly accessbile after removing the case cover, or do other parts have to be removed to get to it?

I'm new to the WR...and have no manual, etc...

Thanks in advance :thumbsup:

You can check the nut by removing clutch cover (small one) and clutch itself, if you want to retorqued it you`ll have to remove right crankcase cover, water pump, etc. Service manual can be found there,

  • YamahaWR450FMike

Posted June 25, 2004 - 03:52 PM


ever since buying my new 04 WR450F I get this pinging noise if I lug the motor just ever so slightly but someone told me it might be the chain. Is that possible?

  • 450high

Posted June 26, 2004 - 12:44 AM


How easy is this to check.Aprox how long a job and the order of removing parts.Also what new parts are required.My 450 has always rattled , as did my 426 . The dealer told me this was normal.I have noticed it is slightly queiter after a oil change.I use yamy lube but is there something better that will make the bike quieter.
Thanks dave.

  • stuyoung

Posted June 26, 2004 - 08:27 AM


Check out my photos on ...
Its the retaining bolts on your rotor / stator. Check them ASAP or you will be in for a massive bill like I was.

  • rekless

Posted June 26, 2004 - 01:44 PM


I think I'll check mine this week. Thanks for lookin' out!! I'm assuming your talking about the smaller allen head bolts, not the big nut in the center?? Also do I need to drain my oil before removing the cover? Thanks, rekless :thumbsup:

  • 450high

Posted June 26, 2004 - 10:19 PM


stuyoung. Good photos.Is this the same problem that the other threads pointed to or another problem.Mine has 1300 k's and i have already done a fly wheel key.I updated to 04 parts at cost thanks to my dealer.Once again i think that maybe the wr 250 2 smoke is starting to look a more reliable option ?.
thanks dave

  • simch

Posted June 27, 2004 - 04:36 AM


Which cover do I remove to check this on my 04? Is it the full clutch cover on the kickstart side, or the stator cover on the other side?
I note people mention the right hand cover, but am not sure if this is when sat on the bike (presume so) or when looking from the front!
I have looked in the manual and the "primary drive gear" is only mentioned in one section on the clutch, and it seems to be the same part that is called the "clutch housing" in the schematic diagram (# 18 on the diagra on page 4-49 of the manual).
I'm pretty confused by all this as my bke is new and I have not had it apart yet, only changed the oil!

Knew I should've stuck to the CR250!! :thumbsup:

  • Lowedog

Posted June 27, 2004 - 09:24 AM


Primary gear is on the clutch side. You can get a look at it by just removing the clutch cover and the clutch. But if you need to tighten it you will need to remove the whole right side cover. Your manual tell you how to do this.

Looks like I better pull the rotor side off again and have a look at those bolts the others are talking about.


  • simch

Posted June 27, 2004 - 12:05 PM


Thats why I was confused, the allen bolts are presumably on the other side, ie stator side.
You say the "whole cover" needs to come off to retorque it? Is there 2 parts to the cover, mine seems to just be one part. And I presume the clutch side is the right side when sat on the bike, not when looking from the front.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Lowedog

Posted June 27, 2004 - 05:56 PM


Yes the clutch side is the right side while sitting on the bike. The clutch cover is the round part of the right side case cover. It will come off independantly of the right cover. If you need to retorque the primary gear nut you will have to take the whole cover off to get to it. Take a look at your manual. The diagrams are pretty good and you will get an understanding of what needs to be done.

The "allen" bolts are on the flywheel. I checked mine tonight and they were tight. No problems there.

3000+ miles on my bike and the only problem I have run into is the loose primary gear nut.


  • mparrish

Posted June 27, 2004 - 06:17 PM


I have an 04. I wonder if it was a problem with this years bike? How did the bike run once this started happening? Besides the noise.

  • simch

Posted June 28, 2004 - 05:31 AM


I ust checked mine and the nut appeared to be ok. There were about three threads showing on the end of the crank too.

I'm not sure how this bolt can come loose as there is a lock washer clamped underneath the nut, which can't rotate because it is also clamped to clutch housing. Is this a "mod" on 04s or do the 03s have this also? If they do, how can the bolt come unone!?

So having said all this, my motor still sounds a bit noisy, (rattly) the noise decreases slightly when the clutch lever is pulled in suggesting some of it is clutch noise.

Maybe I'll check the stator bolts next...??

By the way, has anyone had either of these faults on 04 450 models yet?

  • Lowedog

Posted June 28, 2004 - 12:13 PM


Bike ran fine with the loose primary gear nut. It is held in place with a lock washer so it couldn't back off any further. I am thinking some of these were not torqued properly at assembly. I wouldn't think with the tab bent up holding the nut and torqued at the proper setting it could back off that much.

These motors do make a lot of noise though. All the high performance 4 strokes do. Wear ear plugs. That's what I do. :thumbsup:


  • tracerbullet

Posted June 28, 2004 - 02:45 PM


I have the 2000 400 and it makes a lot of noise also is this A known problem for this bike also. And I don't have the proper manual I downloaded the 03 450 manual better then nothing so info on the noise and manual would be great

  • Kossu

Posted August 06, 2004 - 06:07 AM


The primary gear nut was loose again, have driven 1000km after i first time tightened the nut. On second time i used loctite on grooves, hope it will hold this time.

Here`s picture of my bikes crankshaft, you can easily see how much grooves have worn.

Posted Image

  • Richard WR

Posted October 30, 2010 - 08:17 AM


Hi Kossu and everyone, I have a 450 - not sure if its an 03 or 04. The book was published
Aug 03 and the bike is registered on an 04 plate in the UK. Any how it has become noisier enginewise and I am looking at the primary gear nut fix. In the book is it 14 on page 4-49?
Do I need the special tool - clutch holding tool?

  • kikkokrash

Posted October 31, 2010 - 11:51 AM


my motor still sounds a bit noisy, (rattly) the noise decreases slightly when the clutch lever is pulled in suggesting some of it is clutch noise.

Maybe I'll check the stator bolts next...??

By the way, has anyone had either of these faults on 04 450 models yet?

I have a 03 WR and the engine noise decreases when I pull in the cluch lever. I bought it used in 2006 and so far the sound didn't get better or wost. I shouldn't worry much about that.

If you have a 03 WR you better upgrade to WR 04 the e-starter. I had once the spin weel bolts untightened and once broken! The spin wheel chewed the Stator and the copper wire was chopped from the gear wheels.:smirk:

TT Forum helped me understanding what was the problem. This might be helpfull for you (I think it was made in 2006):

04 Starter Conversion Instructions - Courtesy of TT'er to Dan Djokovic (Indy_WR450):

[COLOR="DimGray"]Purchase Retrofit Parts

The parts needed:
04 Left Side Case Part # 5TJ-15411-10-00 @ $ 92.49
The Left Side Case is NOT necessary!! You may instead, purchase the stand alone bushing (Yamaha P/N 90380-10002-00, Bushing, Solid)
The bushing presses into the existing '03 cover and accommodates the shaft for the torque limiter (smaller diameter than the '03 gear.)
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 total
Gasket for side cover (not shown in pic) Part # 5TJ-15451-00-00 @ $ 4.49

Total cost $338.94 plus tax[/COLOR]

If you need I should also have the procedure.

  • Richard WR

Posted November 01, 2010 - 01:40 AM


Mine is a 2004 model. The noise doesn't change when the clutch is disengaged. Looking at the primary gear nut fix. In the book is it 14 on page 4-49?
Do I need the special tool - clutch holding tool?


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.