All sorted. Exactly what you said. Once the cover was off the bolt was less than finger tight.

Due to lack of time and space I booked it in to my local Yam dealer. After a few phonecalls they establish that Yam are aware of the issue, but have made no manufacturing changes in this area since the birth of the new Tenere. He checked all the torque setting for each year and the part numbers remain the same.

Thanks very much for your help!