Just cleaned and inspected my front sprocket, a quick measure and it appears to be 9 mm or so thick, should it be 12mm??
Its locked on with a bendy washer thingy and has about 1-2 mm of spare thread showing.
Probably original chain and sprockets.
02 fzs600 by the way.
Cheers for the help.
Nick
When your bike was made 9mm was the correct thickness of nut. In cases where there was a problem with it coming loose the Yamaha fix was to replace the nut with a 12mm thick nut. Also if the threads on the gearbox shaft where not as they should be, to replace the shaft.
When fitting a new sprocket it would seem prudent to fit the 12mm nut at the same time. Some folks chose to replace the 9mm nut with a 12mm nut just for peace of mind, (that's what I did), others consider this a bit over the top. Either way using the correct torque and thread lock as well as the locking washer is still important.
Limax2 thats a brilliant drawing thats exactly what i have. I got the bike with 6000 miles on it 2 years ago it now has 15,000 so obviously not a problem.
When i change the chain and sprockets i'll worry about it then, and in the mean time monitor it.
Thank you so much for replying.
Nick