Please listen to my starter and tell me what's wrong

Thanks, crooks420! I think I found something that will work (all are too long, but I suppose I can shorten one). I've ordered a couple to have one to mess around with.

After having read about bearings/bushings on the mcmaster website, and looking very closely at the one in my starter, I'm convinced it's plastic. In fact, upon magnified inspection of my out of whack bushing, it's melted! :lol: I guess the moral is as duke2au said: the starter is for emergency use only.

I'll let you guys know what the outcome of my bushing replacement attempt is.

there all pretty much junk !i replaced every part on my 03 and it still sucks,i just kick it and only use the button when i am on a off camber hill .i thought by 05 yamaha would have fixed there mistake but i guess not ,on the flip side i am at 6000 miles with no valve adjustments! and yes i do check them

I read a couple of posts on this thread that implied one could somehow "shim" a sloppy bushing. I'd sure appreciate some tips on how this might be done (at least as a stop-gap method to ride this weekend).

The shims I was referring to in an earlier post would be for the axial direction. That is, if there wasn’t enough axial play to allow free rotation (remember to allow a bit of extra clearance for thermal expansion mismatches between the different materials in the starter) then that could have been the cause of the squeal. However, since you didn’t mention abnormal wear on the end of the bushing nor on the end of anything else, I doubt this is the case. An out-of-round bushing (like what you found) would certainly explain the symptoms you experienced. The only way I know to fix an out-of-round bushing is to replace it. I’m sure the bushing came that way from Yamaha too (but will also rapidly get worse with use). It’s pretty easy to manufacture them this way (by accident of course), and it probably just got through Yamaha’s quality control. In my opinion, this is a workmanship problem which should be covered under warranty, but that’s a whole different issue in itself.

Great update so far and I hope those bushing you got will work for you. I look forward your update.

By the way, “plastic” does not necessary mean bad. Vespel is a great material, but also very expensive. I was surprised to see that McMaster Carr had Vespel bushings to offer, but the cost is steep. !!Ouch!! :lol:

It's late in the 4th quarter and I'm down by several points.... Unless someone can steer me toward an exact fit bushing, I will lose this game and have to buy a new starter. It's become the principle of the thing at this point--a screwed up $10 bushing shouldn't equal having to buy a complete starter for $200+.

The bushing I ordered is one mm too small in the outer diameter, and it doesn't look like they make one (I can't find it on McMaster's website) the correct size. It's dimensions are inner diameter 9mm, outer dia. 13mm, and length ~6.4mm (I figure the length can easily be modified from the 12-14mm that the bushings are sold as). The closest I can find. and what I bought hoping to make it work, is 9X12. I see nothing nX13 that will work. It also needs to be out of "self-lubricating" material.

Incidentally, and perhaps critically, I didn't see the Vespel bushings rrleidt referred to--at any price. I agree that "plastic" is not always bad as well, but when a bearing melts, something seems wrong.

I hope someone can throw me a touchdown pass!

Can't you just fill the 1mm gap with JB weld making sure it is centered then put some grease on it?

if you are in the 4th, slap it all back together and kick it. Field goals help.

go riding, have fun. On Tues. you can get back to figuring this problem. Figure it out, and make a ton of $$ selling it to us.

John in Vegas

My YFZ450 was making that same sound. I took it apart and the teeth on the end of the starter were worn off. It had somehow pulled away from the starter gears and just had enough teeth there to grind off the edge of the starter.

It's dimensions are inner diameter 9mm, outer dia. 13mm, and length ~6.4mm

Bummer, an odd-ball size. I browsed around on a few websites that I knew of and didn’t find any that size. A machinist could make one, but that wouldn’t be cheap either.

Did you notice this webpage: It references yamaha part number 90380-10002-00 and has a picture of it in the left-side crankcase cover. I can’t tell by the picture, but it looks like it might be the same size as the one your looking for???? You can probably see a lot easier on your own torn down bike.

The partsfishe on had these parts (although preceeded with a “Y”), for only $0.78

Some smart guy (look at the credits at the top of the wr450 webpage) knew that the bushing had it’s own part number… maybe that same guy knows how to find the part number for the starter bushing.

By the way, McMaster Carr carries only english size vespel bushings – no metric. I got to these by clicking plastic bushings, then vespel.

I recall that a while back some of the TT guys rebuilt the starters using some non Yamaha parts. Use the search engine here to check it out.:lol:

my 03 made the same noise,but much worse. the problem was the soft bushing where the starter shaft seats into the starter housing. It had become elongated and needed to be replaced. I did not want to but a new starter, so I removed the bushing and fabricated a bushing out of 3/8" brass pipe nipple(i think that was the size). I know it sounds hokey, but it worked. I don't know how long it will last, but it was alot cheaper than a new starter.

Ok.... back to McMaster-Carr......

Search for SHIM STOCK, look at the roll/ sheet stock, I believe they have 0.5mm Stock..... which should make up for your 1mm OD difference......./........


These McMaster part numbers might work....?

9014K33 9011K3


Here is a recording (from a helmet cam) of my '06 WR450 (all free mods) with ~600 miles on it. The starter gradually started screeching like this, but has gotten worse and worse, to the point it sounds like it's gonna blow up. Click here to play .wmv file of horrible starter noise.

Sounds like some dry bearing(s) or bushing in there..?

I finally have some time to give an update.

To recap, I couldn't find the right size bushing. I ordered one made of Rulon LR ("A self-lubricating, reinforced PTFE material that doesn't absorb water and resists most chemicals" that had the correct ID, but was 1 mm too small on the OD.

I didn't feel comfortable just JB Welding it or the like, and I didn't feel capable of doing the shim thing myself, so I paid a guy $30 to shim it for me. (I was thinking that I wanted something to last at least a little while, not just jimmy-rigged.) I'm now into it around $40.

Well, it turned out better than I expected--so far, that is. The starter purrs and seems back to where it should be. I haven't had it out on the trail, yet. The real test, of course, is time. I'll update this thread if it lasts or if it doesn't.

I really had hoped for a solution that I would have more confidence in its durability. The solution I came up with is not very elegant. Had I been able to find the right size bushing made of a self-lubricating material, I would have figured I nailed it. If anyone does find such a bushing, I'd appreciate it (along, I assume, with several other TTers) if you'd give details as to how to get one.

Thanks to the many contributions and supportive ideas you all gave. :lol: This place is amazing!

Just for those that have the same problem in the future do the fix right and buy:

9mm id x 13mm od Rulon bushing x 10mm long and cut it to the length needed without the need to shim!

Rulon is an excellent dry self lubricating bearing material.

Rulon-Meldin Part # MRS0913-10 is a sleeve and #MRF0913-10 is a flanged end sleeve.

Go to page 16 of this catalog:

US Distributors of Rulon-Meldin Products:

I bookmarked this page.....I hope it works when my starter goes south.....thanks all for sharing the good info. I'm going to kick start to start first time in the day from now on, then use e-start.

Here is a recording (from a helmet cam) of my '06 WR450 (all free mods) with ~600 miles on it. The starter gradually started screeching like this, but has gotten worse and worse, to the point it sounds like it's gonna blow up. Click here to play .wmv file of horrible starter noise.

I had the same problem with mt 03 wr450f pulled the starter off and totally dismantled it and there was a lot of dust through out it I put it down to the dust coming off the brushes blew all parts out with a compressor and lubed all parts up with WD40 and dried off put it back together runs like a dream Its a common problem with the Wr's Give it a go and you'll be back on track.....:applause: :applause: :lol:

Well, I have about 100 miles on the rebuilt starter (pity me for only having had time to put that much on since the rebuild!) and the thing is purring fine. I must admit I treat it differently since the (literal) meltdown. I grind it for shorter times (much less than the 10 seconds the manual says), I give it a rest between attempts, prime it when cold (throttle twists--see manual), and pull the hot start when hot (I really never used the hot start much before). I'm hoping these changes in my use of the starter will make the thing last. I can't bring myself to just using it in emergencies, perhaps because I'm 47, not limber, have had right knee troubles, and believe "the button" is what separates man from the rest of the animal kingdom.:applause:

I agree w/ MSGBean, sound like the starter motor bearings are starving for lube. I've never done it but, cant help but think you could take the starter apart and apply grease to the motor shaft bearings.:applause:

It sounds like my 03 starter clutch. I have a spare for an 03 wr450. dont know if it will work on any other models. Will sell reasonable as I just got an07 wr450. Working on the mods. The starter clutches are USUALLY easy to fix if you are mechanically inclined. The whole starter function depends on a very small spring to hold all the one-way bearings in place. Problem the spring becomes stretched and distorted and the rollers CHATTER making the screaching sound. find the right size spring and fiz it. Cheaper then a $200 starter clutch and it works like a champ.:applause:

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