The dreaded front sprocket nut!

[Joolz]

So it seems to be a thing! After hearing a noise, I removed the front sprocket cover to find the nut just sitting loose on the end of the shaft, not a hint of thread left in it. I bought a new nut from the dealers and came on here looking for a torque figure for it, turns out its a common fault and that most people, including Yamaha, know about an upgrade to a wider nut.


So how come my dealer in Carshalton sold me a 9mm nut and claim no knowledge of any other part, the dealer in Twickenham also claims ignorance, and even Yamaha UK say there is only one part number suitable for a my bike and that's for the 9mm nut I've been given?


Despite all the related threads on here I couldn't find a part number mentioned for the 12mm nut, is it a genuine Yamaha part?

[darrsi]

http://foc-u.co.uk/index.php/topic,15630.msg178827.html#msg178827

[Joolz]

Thanks darrsi, I see the ebay listing there,


http://www.ebay.co.uk/itm/GENUINE-YAMAHA-FZS600-FAZER-FRONT-SPROCKET-NUT-AND-WASHER-KIT-/141276105948?pt=UK_Motorcycle_Parts_13&hash=item20e4b64cdc


It's just confusing me that what it says in the listing isn't backed up by the dealers.

[darrsi]

You'll have to do a deep search on here, but somewhere there is a copy of a letter from Yamaha recognising the problem with a service note ID number on it.
I s'pose you have to take into consideration these bikes are at least 14 years old now so unless presented with the problem then chances are that staff won't know about it, unless they've been in the business a long time.
Mechanics would be more aware of it though, i'd imagine.

[darrsi]

http://foc-u.co.uk/index.php/topic,17543.msg202280.html#msg202280

[Joolz]

I found the tech bulletin where Yamaha accept the problem and advise dealers to change to nut, but I notice that they only think there was a problem with '99 models onwards, if I had said it was a '99 and not a '98 would I have got a different answer from the guy on the parts desk I wonder?


I also noticed that the bulletin was issued by Yamaha USA, were the UK dealers similarly notified?


I'll go down the dealers and see what response I get claiming it's a '99 model, and then order the part number in the ebay listing anyway.

[celticbiker]

There were similar issues with the tdm 850's  and the xt 600.
Part of the problem there was the after market sprockets though, apparently they were ever do slightly thinner than the original.

[fazersharp]

I found the tech bulletin where Yamaha accept the problem and advise dealers to change to nut, but I notice that they only think there was a problem with '99 models onwards, if I had said it was a '99 and not a '98 would I have got a different answer from the guy on the parts desk I wonder?


I also noticed that the bulletin was issued by Yamaha USA, were the UK dealers similarly notified?


I'll go down the dealers and see what response I get claiming it's a '99 model, and then order the part number in the ebay listing anyway.

It will come off if it has been replaced in the past and not correctly torqued with properly bent washer tabs and lock thread whatever the year, so yours (im assuming has had them replaced from factory fit )  would be down to user error. ( They would say )

Here is what I have

[darrsi]

That's all very well, and is a replicated version of the issue, but that paperwork doesn't even mention our bikes at all so can't be presented to a dealer. 


It's "SERVICE NOTE 2005-12A" which lists our bikes.

[darrsi]

http://foc-u.co.uk/?topic=92.0