Changes made by Council Directive 78/1015/EEC of 23 November 1978 on the approximation of the laws of the Member States on the permissible sound level and exhaust system of motorcycles
EU Directive 1978/1015
No changes made by Council Directive 78/1015/EEC of 23 November 1978 on the approximation of the laws of the Member States on the permissible sound level and exhaust system of motorcycles are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.