front Sprocket Nut Dealer Problem.

[Dcock]

Just a quick question. My sprocket nut is the old style nut, but it is not loose. Should the local dealer replace the nut FOC? If so does this have to be during a service or can i literally just take it to the dealer for them to change the nut without paying for a service. Thanks.

[Dave48]

The modified(thicker) front sprocket nut & lockwasher comes as Yamaha part no: 90891-10124 & cost me £2-44 from my local Yamaha main dealer.
It is a fairly simple job to do if you have the correct tools & knowledge. Have you got a Haynes manual?  If  you prefer not to do yourself :eek  the dealer would prob charge 1/2 hours labour. This issue has been well documented on the forum-enter "Front sprocket nut problem" in search box for more info if required. Although Yamaha are well aware of the problem they never issued a recall but the consequences of a sprocket coming loose can be dire in terms of cost(stripped output shaft splines) or causing lock-up of final drive/loss of control/accident. :eek

[andybesy]

In case anyone's interested I was eventually able to get hold of a copy of the Yamaha service bulletin relating to the front sprocket issue, which I've just uploaded here:

http://foc-u.co.uk/index.php?action=down...file&id=50

Not sure if this has been circulated before, there's been so much discussion of this issue it's hard to check it all.

I understand a "technical bulletin" is like a recall but less serious; it's something that gets fixed as bikes come in for services, as opposed to calling them in especially.

Although it unfortunately doesn't explicitly mention the FZS, it does say "fix it for free irrespective of warranty status".

I took that to my dealer and explained that the FZS also seems to be affected (although I didn't go so far as to ask them to do it for free).

Andy

"In some cases, the drive sprocket
retaining nut lock washer can allow
the nut to rotate just enough to
reduce the clamping force resulting
in fretting the drive sprocket retaining
nut and lock washer."

[nick crisp]

All Yamaha dealers are sent copies of these service bulletins when such issues arise. However, over time they can easily be forgotten, as they receive so many such bulletins over the course of a couple of years for all the different models, and some dealers may never have been approached by customers with relevant "problems". However, they can always contact Yamaha UK to check on such issues. At one dealer I worked for, for nearly five years, I hardly ever recall seeing the front sprocket nut problem, but at another place I only worked at for about 3 years, it was something we checked on with every FZS600 that came in.

[andybesy]

Yup, makes sense. I got one who wasn't especially familiar with it, and so the issue I came across was that they searched their computer for service bulletins against the FZS model, and responsed "there isn't one".

The printed copy helped me to explain what I was asking for.

[darrsi]

Nice work Andy, that's some good ammo to approach a dealer with to get it sorted if you're not really a hands on person, or haven't got the tools.