William Scott's car was so long that motorcyclist David Roberts had no way of avoiding it as he came round a bend and the impact left him fatally injured.
Scott, 73, was not sent to prison after a court was told he had driven more than one million miles without incident in almost half a century of motoring.
Perth Sheriff Court was also told that residents had put a mirror up to help drivers at the junction - but it had been covered with a sheet and then removed by Perth and Kinross Council which refused to give it planning permission.
Scott's manoeuvre was carried out after he consulted his sat-nav system and was informed he would have to turn back to reach his destination.
Mr Roberts, 41, from Stanley, Perthshire, was returning from a business meeting on his Ducati motorbike.
The father-of-three was treated by paramedics but pronounced dead at the scene as a result of the impact. The court heard he had been driving normally at the time of the crash.
Scott, of Overtown, Wishaw, admitted that on August 22, 2012 at the A85 between St Fillans and Comrie he caused the death of David Roberts by driving carelessly.
Solicitor Richard Freeman, defending, said the trauma of the crash and its consequences had forced Scott to shut down his cladding business.
Sheriff Fiona Tait banned Scott from driving for 30 months. She also ordered him to carry out 300 hours unpaid work in the community.