Tiger 955i rumbling noise

[Keeper96]

Just been out and out 170 miles on my tiger 955i

On the way home I noticed that on the overrun at around 10-30mph there was a noise I can only describe as a scratchy rumble from the engine area, it may have been there at higher speeds but too much noise to hear it, it would go away when the clutch was pulled in and I could recreate it by pulling and releasing the clutch whilst in that speed range. 

I couldn’t get it do make the exact same noise on the centre stand but if I got it upto 3rd then there was a lot of noise from the front sprocket area. 

My initial thoughts were clutch release bearing but with the noise from the sprocket I’m not too sure anymore. 

Any likely culprits to investigate?

[Mississippi Bullfrog]

How is your chain tension and condition of chain / front sprocket? 

Edited June 21, 2021 by Mississippi Bullfrog

[Keeper96]

2 hours ago, Mississippi Bullfrog said:

How is your chain tension and condition of chain / front sprocket? 

Chain tension appears to be good according to the specs I found 

 

I’ve just whipped the front cover off and found the nut holding the front sprocket to be loose, only being held in place by the lock washer.

there is a slight amount of play in the front sprocket but I’m putting that down to the nut being loose. 
 

would you suggest the best course now is to fit a new washer and retorque the nut or would you investigate deeper? 

Edited June 21, 2021 by Keeper96
Added pics

[Mississippi Bullfrog]

Those washers are reusable so you usually can tap them back into place. That washer looks to be bent over correctly so the nut shouldn't have been able to work loose. Are you sure it is loose or is the sprocket just moving on the splines slightly? I'd tap the locking tab back and check the torque of the nut. 

[Keeper96]

26 minutes ago, Mississippi Bullfrog said:

Those washers are reusable so you usually can tap them back into place. That washer looks to be bent over correctly so the nut shouldn't have been able to work loose. Are you sure it is loose or is the sprocket just moving on the splines slightly? I'd tap the locking tab back and check the torque of the nut. 

Yeah the nut is definitely loose, I can rock it side to side with my fingers

 

 

 

i’ll retorque it later and ensure the washer is properly bent over then go for a test ride to see if the noise disappears.

[Keeper96]

Ordered a full sprocket and chain set today with new washer and nut. 
 

the only thing unsettling me is why it would come loose in the first place? 
 

any ideas 

[Bender]

May not have been put on correctly last time it was off. 

[Mississippi Bullfrog]

56 minutes ago, Bender said:

May not have been put on correctly last time it was off. 

That's what I'd suspect as well. The locking tab was clearly tapped over securing the nut. So it suggests it wasn't torqued up properly in the first place. Maybe whoever did it hadn't locked the chain from moving.