Norton Service Release Database N46

SERVICE RELEASE N46

NATURE OF RELEASE: Intoduction of "S. E. " piston rings (oil control) MODELS AFFECTED: 1971 Commando Engine Number 146584-147176, 147259 onwards DISTRIBUTION: Worldwide (for general distribution) EXPLANATION: Spring expander type oil control rings have been introduced on the motorcycles specified above. The piston bodies are revised to accomodate the spring expander type of ring and for this reason it is not possible to use the later rings on an earlier piston or vice versa. For spares purposes the revised pistons with rings as a pair can be used to advantage on previous Commando models. It is not considered good practice to assemble an engine using one old type and one new type piston. The part numbers of the old and new components are detailed below:   ACTION: When replacing pistons or piston rings ensure that the correct parts are used as detailed above. June 1971 Norton Villier Canada Limited