24-01-12, 09:41 PM
From your post count Edc it looks like you could be fairly new here, so first off welcome to the site.
The part number for the new 12mm thick nut complete with locking washer is 90891-10124. Always better to quote that number otherwise you could still be supplied with the old 9mm type by dealers.
I have measured the thread on three bikes and they were all round the 17.85mm mark and none have had a problem with the nut coming lose. A number of bikes were supplied under size and resulted in a stripped thread. Of course even with a good thread on the shaft it still has to be assembled correctly i.e. clean thread, loctite, and correct torque. Having said that Yamaha U.K. recommended 90Nm torque with the new nut but I have stuck with the 70Nm originally quoted and never had a problem.
(24-01-12, 05:38 PM)Major Rant link Wrote:Also to replace the gearbox output shaft if the thread was below that size.
The solution was to measure the O/D of the output shaft and if it was below a certain number (17.5mm IIRC) then fit a new (different) sprocket, nut and washer.
The part number for the new 12mm thick nut complete with locking washer is 90891-10124. Always better to quote that number otherwise you could still be supplied with the old 9mm type by dealers.
I have measured the thread on three bikes and they were all round the 17.85mm mark and none have had a problem with the nut coming lose. A number of bikes were supplied under size and resulted in a stripped thread. Of course even with a good thread on the shaft it still has to be assembled correctly i.e. clean thread, loctite, and correct torque. Having said that Yamaha U.K. recommended 90Nm torque with the new nut but I have stuck with the 70Nm originally quoted and never had a problem.