Norton Service Release Database N3/21

SERVICE RELEASE N3/21

NATURE OF RELEASE: MODELS AFFECTED: All 750 C. C. Commando models DISTRIBUTION: Worldwide EXPLANATION: 1. A revised cylinder head gasket, part number 063844, has now been introduced on all production models from engine number 212173. The new gasket incorporates steel fire ring 'eyelets' which provide a more positive gas seal under arduous conditions. This new gasket is fully interchangeable and should be used as a direct replacement for the earlier cylinder head gasket 060400. 2. An alternative (thicker) copper gasket is now made available through Spares channels under part number 064071 (1mm thick 0.040in. nominal). 3. 064072 (2mm thick) copper gasket is vailable for markets where a reduction in compression ratio may prove desirable to meet local fuel availability requirements. Use only H.M.P. grease when assembling either type of cylinder head gasket. Fit the non-metallic type under dry cylinder barrel to head conditions. Removal of cylinder base gasket NM24249 necessitates the use of an alternative joint sealing compound (e. g. Douglas Kane Loctite "Instant Plastic Gasket").   September 1972 Norton Villiers Canada Limited