one way Starter Clutch and 04 upgrade parts question (PIC)

27 replies to this topic
  • duke2au

Posted October 30, 2005 - 10:27 PM


I know this has been done over and over, but I am having troubles determining what the torque limiter is in the 04 upgrade... or at least what it does. which is it in the pic below?

I think that I will need to replace my "one way" clutch, but do I really need to get the 04 upgrade as well?

The 2nd idler (part 10) does not spin both ways by hand. I can spin it one way freely and push it with a flat screwdriver the other way which seems to rotate the flywheel. With the idler gear in (parts 4,5,and 6) but with the cover off it will not spin the flywheel when I hit the button, It just seems to grind.
I am seeing this as the starter clutch which is the problem... Am I on the right track, or does this same symptom have something to do with the 04 upgrade parts?

Posted Image

  • Indy_WR450

Posted October 31, 2005 - 06:41 AM


Here is my write up with pics:

The starter clutch can fall apart into many pieces and may need replacing.

  • duke2au

Posted October 31, 2005 - 01:17 PM


ok Have a version of your write up, but it seems to be cut down a bit. The new 04 limiter part seems to be much different from what i am pulling out of my 03. Is it a completley new design? If so, what is the new design supposed to achieve? I thought the problem with the starters was the one way clutch and the brushes and / or the bushes?? It looks to me from your write up all I will be replacing for the 04 upgrade is parts 4,5, and 6 in the diag above?? (you seem to have these 3 parts assembled in this pic).
The bottom line is that everyone says you need an 04 upgrade. Go buy all these new parts that will fix the starter problem, when in 90% of all starter failures, its the starter clutch behind the fly wheel thats the issue. I must be missing something here...

  • Indy_WR450

Posted October 31, 2005 - 01:24 PM


The key to the 04 upgrade is the new torque limiter to eliminate the famous woodruf key failure. The starter clutch should be left alone if it has not fallen apart. Some people have had the starter clutch crumble into many pieces. These are separate issues. The torque limiter will prevent possible case damage and other expensive damage associated with a backfire. :banghead:

  • duke2au

Posted November 01, 2005 - 02:03 AM


ok, I havent had the woodruf key problem.I am aware of it, but I am confident that I shoudnt get it as (fingers crossed) I should of had it allready. My Fly nut was re-torqued when the bike was new.
Having said that, my one way clutch seems to be shot. This is some thing that I should replace no matter what to get this starter to engage.

I suppose my question was, do I need the "04 upgrade" to prevent my new starter clutch from busting again?..suppose the answer is no.

I was also thinking that maybe before doing the "04 upgrade" some might experience simular symptoms as if the oneway clutch was broken. I suppose the answer to that is no as well...

Thank you for your info. I think there has been so much hype about the "04 upgrade" that some are thinking that it will fix starter problems, when in fact all it does is prevent the woodruff key from shearing. (still not technically clear on how) This seems like a not so important upgrade after all, considering that yamaha made steps to rectify that problem with the original 03 bikes.

In a "nutshell" this is what I have learnt from this site: :banghead:
starter problems could be related to the following on the 03 WR450's:

1.Low amps from the battery causing a relay clicking sound - recharge or replace Batt
2.Bad connections resulting ion low amps causing a relay clicking sound - re-terminate connections. Check relays too, steps are in the yami manual.
3.Bad brushes on the starter - replace brushes (25$aus yami part) or replace starter.
4.Worn bushing in starter causing the core winding to hit the magnets. - Get a new bushing made (yami does not supply bushing) or replace starter.
5.Bad windings in the starter motor. replace or re-build starter motor
6.Bad "oneway" assembly behind flywheel which will not engage the flywheel to turn over the engine - replace with yami part which will require flywheel puller.

The 04 upgrade applies to when your in the middle of the bush and you have sheared off your woodruff key from bad jetting or bad luck causing a backfire. Doing this will result in you hitting the magic button over...and over...and over again trying in vain to start the bike. You wont be able to start the bike as the timing has altered preventing a start. By using the "magic button" so much, is a sure fire way in getting at least one of the 5 symptoms above to present itself. :banghead:

  • BajaFool

Posted November 03, 2005 - 03:10 PM


You have summed the situation in excellent fashion. Just remember, the part number is the same for the 2003 through 2005 Starter Motors. This means that if you replace your starter motor, there is no "upgraded" starter motor available, just a new starter motor that may or may not have been manufactured after 2003.

If you want to see a picture of the difference between the 2003 and 2004 Starter Clutch Gear Assemblies, go to <>. There you can click on the parts catalog feature, then click on the pages for the 2003 Starter Clutch and you will see the Idler Gear Assy. that is engaged by the Starter Motor, note that parts 1-4 go together and are part of the same assembly. Parts numbered 5-9 are part of the same assembly and make up the Starter One-Way Assy. that is located behind the Flywheel Assy. Clear the parts catalog page information, enter the data for a 2004 WR450F, open the page for the parts that comprise the Starter Clutch and you will see that parts 1-4 go together and comprise the Damper (Torque Limiter) Assy that is engaged by the Starter Motor. The Torque Limiter Assy. Part Number 5TJ-15560-00-00 replaced the Idler Gear Assy. Part Number 5TJ-15512-00-00 found in the 2003 model WR450F. The Parts that are numbered 5-9 are part of the same assembly and make up the Starter One-Way Assy. Notice that the part numbers are the same for this assembly between years, I checked and the 2005 model is the same part number also.

I think that upgrading the Starter Idler Gear Assy. in your 2003 is a must. I often ride 50-100 miles from any sort of help, if I were to spin the flywheel or crack a side case it could be very serious. I want the peace of mind of knowing that I won't have to subsist on Witchey Grubs washed down with green water from the billabong, while I wait for help that may be days in arriving.

Now, the only thing that I want out of this post is for someone to tell how to enter a web address into a post so that it is a hyperlink that can be clicked on and opened.

  • ncampion

Posted November 03, 2005 - 05:00 PM


Use the "insert hyperlink" icon in the message reply screen.

For example:

  • duke2au

Posted November 03, 2005 - 05:31 PM


Thanks for that.. another penny dropped when you explained that those parts fit together :banghead: I didnt realize that and that made it look a little confusing.
Here is the parts side by side for the other "03'ers".
Posted ImagePosted Image

So this development was purely because the older 03 part can self destruct? I want to understand the torque limiter works. I am imagining that it takes the "crack" out of the starter spindle hitting the idler gear. :banghead:

And for the development of the "one way"... will this new part fit on the 03 as a retro fit? It looks to be re-engineered as well. I heard that Yami will re-engineer, but make the part number the same providing the part was engineered to retro fit. This avoids confusion for their parts depts and consumers.

Also... why do these "blow ups" only show part of the teeth section of the diag? For someone that is trying to learn the assembly, its kinda deceiving. Its great to have these forums to get all the mystery outta this Shiite...

Thanks for the clarification. Its great when you know people genuinely want to help!

  • BajaFool

Posted November 03, 2005 - 10:00 PM


The Torque Limiter on the 2004WR can freewheel backwards if the engine backfires while being started. The Idler Gear on the 2003WR relied on the gears slipping on the axle of the idler gear assy. to prevent damage when the engine backfired while being started.

The picture of the Ony-Way Starter Clutch appears to be different between the 2003 and 2004 parts catalog. However, the part number remained the same from 2003 through 2005 for this part. I don't know what to tell you about upgrades to the one-way assy. If yours shows evidence that the rivets have elongated or are loose, then by all means change the clutch.

As for why they draw the pictures the way they do, you will have to check with Yamaha. I've looked at a ton of technical drawings over the years and I don't see anything wrong with the way they are depicting the parts and their relationship to each other.

  • duke2au

Posted November 04, 2005 - 12:16 AM


thanks again... I know know why I need to do the upgrade. I can explain why it needs to be done rather that saying "someone said it was a good idea". Much appreciated...

Elongated rivets.. I wish.. the whole thing just spins backwards with the starter motor. Like its stripped or something. I have done the brushes, cleaned and greased the motor, reconnected all the electrics; to be presented with a bad starter clutch. At least I know its the last thing in the process of elimination to at least get it to spin over (electrically). Its going to be swapped as soon as I pay off my rad guards and YZ muffler.
And then now the 04 upgrade.

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  • BajaFool

Posted November 05, 2005 - 07:52 AM


Thanks for the instructions on how to insert a hyperlink into my posts.

  • duke2au

Posted November 26, 2005 - 02:59 PM


I finally "bit the bullet" and bought a brand new starter clutch for the WR. I actually got the dealer to do it as I dont have a puller.

I asked if they could change the oil filters as well as they would obviously be dropping the problem.
When I pick it it he says, here is your new filter, we could not change the filter as one of the bolts for the filter housing is stripped and you will need a helicoil. Again no problem... ( beleive that they were not responsible for the strip)

Anyway, I am assuming they couldnt test the new starter clutch as at this point there was no oil in it. I got the bike back home and put a helicoil in the housing and filled it up with oil. I warmed the bike up so I could test the E-button.

you wont believe this!! the same F%#@ problem as when I brought it in. All the previous diagosis has pointed towards the starter clutch.

I just handed over 450 bucks to these guys and still not start.. Every starter component has been prepared for this I am totally pissed.

parts replaced:
Gear 3 5TJ1551500 $121.98
STARTER 1 WAY ASSY 5TJ1559000 $138.36
BEARING 9331022037 $43.11
LABOUR 85.23
(just quietly wondering why I need a "GEAR 3"??)

What do you think I should be doing now? I hope I wont have an issue with the dealer because I told them what to replace. "replace the starter clutch please". Do you reckon they have the right to say "tough luck"?

Is there anything that could have simular symptoms as a bad starter cutch?.. I wouldnt think so!!

I feel like selling this bike. I got a great deal on this one, so you know what they say, "The cheapest man will allways pay twice" in my case 3 times??

suggestions please?

  • duke2au

Posted November 26, 2005 - 03:09 PM


I just wanted to confirm something as well in regard to the rotation of the starter gears:

starter motor rotates clockwise
idler gear rotates counter clockwise
starter clutch rotates clockwise grabbing flywheel and starting bike
starter clutch freewheels counter clockwise

I am 99.99% sure that I have the starter motor spinning the right way as I have tested it, but I just want to rule it out as well.


  • Indy_WR450

Posted November 26, 2005 - 03:55 PM


Make sure your bike can be kick started before you try and fix the electric start. If it starts with kick starting warm up the engine and drive it around for 5 minutes to get her hot. Then turn it off and while she is hot try the e-start.

If your battery is not up to full strength your starter motor will not be able to spin hard enough to start her cold. Put a meter on her and make sure you get full amps during the starter cycle.

Jetting is crititcal to getting the e-start to work. Kick starting is less jetting sensitive.

If all else fails you may just need a new starter motor. These motors weaken over time and cant pull the rpms or torque that a new spec motor can. :applause:

  • duke2au

Posted November 26, 2005 - 04:26 PM


thanks for your input, however the starter motor and batt are fine. I have ridden the bike for a while as well before trying the e button. As far as jetting the bike is stock.

I take the starter gear cover off and watch the starter spin all day long. Thats when I get the grinding noise as I hit the button. But just to clarify, the grind is not from the starter.

I have done all the diag on this and I am sure that its the starter clutch. I am just concerned on what the dealer will tell me.

what are you opinions on how I should "tackle" this?

  • ddialogue

Posted November 26, 2005 - 05:28 PM


thanks for your input, however the starter motor and batt are fine. I have ridden the bike for a while as well before trying the e button. As far as jetting the bike is stock.

I take the starter gear cover off and watch the starter spin all day long. Thats when I get the grinding noise as I hit the button. But just to clarify, the grind is not from the starter.

I have done all the diag on this and I am sure that its the starter clutch. I am just concerned on what the dealer will tell me.

what are you opinions on how I should "tackle" this?

If you get a grinding noise while cranking the starter, it's most likely the starter-clutch. We've seen two go bad now in my bro-in-law's bike (no '04 upgrade parts.) Lots of grinding while cranking. I'm wondering if the failures are a result of the 03 design (no 04 upgrade parts.) Anyway, super easy to replace. His fell apart in our hands so make sure you don't get any parts in the motor. New starter-clutch is about $70.

Here's what his first starter clutch looked like when we pulled it out:

dead starter clutch

  • duke2au

Posted November 26, 2005 - 06:30 PM


Thanks Ddialogue, the thing is that the starter clutch was replaced less than 24hours ago.

  • ddialogue

Posted November 26, 2005 - 08:06 PM


Thanks Ddialogue, the thing is that the starter clutch was replaced less than 24hours ago.

I guess I should have read a little closer! :applause:

  • 450high

Posted November 27, 2005 - 01:08 AM


Duke2au where abouts in aus are you as may be able to help.I,m near geelong

  • duke2au

Posted November 27, 2005 - 01:35 AM


Thanks for the offer, I am on the central coast of NSW. 1 hour north of Sydney


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