Recommended torque

[fazersharp]

If it adds weight to your theory, I can confirm that my recently acquired 5DM1 model was subjected to thorough scrutiny around the gearbox sprocket area. To my amazement I found this twenty six year old bike still had the original 9mm nut fitted. For peace of mind I decided to change it out for the upgraded 12mm version that came in at £3.79. The cheapest genuine Yamaha item I have ever bought. It took me five minutes of bouncing up and down on a 450 mm extension bar to undo the original nut! I really don’t think that one was going to work loose anytime soon. Also measured the shaft at three points and it averaged out at 17.68 diameter which was nice. 
As it’s my first post can I squeeze in a quick intro. Badly wanted a FZS600 when they first came out but I didn’t have the £4000+ required. I had to settle for a two year old Bandit 600 which was a decent bike but not a patch on this Fazer. Only two small gripes so far, the 80’s style agricultural Yamaha gearbox that makes me feel like an amateur when changing from 1st to 2nd and I can only see my right elbow in the offside mirror! Endearing idiosyncrasies I suppose. Cheers all.

PS. Tried to post a pic but it came out sideways so I deleted it.

Thanks for that. Some have tried to debunk my theory but none have managed to and as the 98 is getting old its almost impossible to find one with the original chain/ sprockets. Some have said " I brought a 98 and the nut came off" -- but it then transpires that the sprocket was previously replaced so you have to take account of error when it was replaced.
In a nutshell my theory was that the first bikes came out of one factory but then as they proved very popular and the parts - shaft were outsourced or whatever but they were not all the correct spec. Explains why no 98 has the issue and also why some newer ones do and others dont.

I had the 12mm nut ready but just waited until I changed he chain and sprockets and put the new nut on then.