Loose front sprocket nut on a Yamaha MT09. Dangerous.

Went to change chain and sprockets then revealed the front sprocket was shockingly loose.
A common issue on some Yamaha’s
#doncastermotorcycles

[@Lunas11]

Old Yamaha FZS 600 had same problem. Instaling a locking washer was used old days to sort these problem out.

[@h4xi0rek]

I discovered the exact same thing on my FZ6 once I began chain and sprocket replacement. The front sprocket was holding onto the shaft only thanks to the locker washer. The nut was so loose that I could easily turn it with my fingers. Guess I will have to check it out now, 15ths kms after replacement :p

[@gianniiacopini9864]

Yamaha says to replace the nut every time you undo it and that's because it's a special nut that has a lip that has to be crushed where the 2 opposite notches on the rod are. My dealer didn't replace it because they didn't have it in stock and they said to me that the nut was reusable as long was in perfect shape, but guess what... I found it loose as it was time to switch to a 520 chain-sprockets.. It was just hand tight. I was there when the dealer reused the nut and they did crush the nut lip as they should do but a new nut would have been a better choice, after all

[@y00tiuby00zr]

Same thing happened to my MT07 i discovered it today during cleaning. At that time, I was also trying to find out what’s causing the noise coming from the front sprocket especially during deceleration. So shocked to find out the nut was so loose I could take it off the shaft just using fingers, without using any wrench.

[@j_gleck1310]

Found out this was happening to my mt07 a few weeks ago, kept torquing it to spec value (69 ft-lbs) and it kept coming lose, lmao. this time i had the bad idea if torquing it to 80 ft lbs…. Lets hope it doesnt cause problems

[@elindenstein]

Yamaha went way overcompensating on this because I have tried everything to get this front sprocket nut off of my T7 and that thing IS NOT budging.

[@serbiantennis]

Same on my mt09. I thought it was mechanics fault, but now I see it's a common thing. Any ideas?

[@D2TEP]

plenty of thread lock and correct torque setting

[@MegaPaddles]

The front sprocket on my mt09 keeps coming loose even after keeping to the torque specks, any ideas what could be causing it

[@D2TEP]

put loads of thread lock on

[@MegaPaddles]

@@D2TEP ive tried that, it doesnt work sadly, ive put the bike into a mechanic now, need to sort it out

[@D2TEP]

@@MegaPaddles have you tried with a new nut?

[@MegaPaddles]

@@D2TEP yes, new nut and washer

[@SH-vo6go]

Could it cause chain bad loop ? Noisy ?

[@j_gleck1310]

Yes. it makes chain and drive system noisy and clicky sounding

[@darielsabay1391]

just put a blue locktite on it

[@DavidM2002]

That's exactly what I did on my CBR. No mention of it in the manual but it won't hurt and can quite possibly prevent a catastrophic result.