Norton Service Release Database N63

SERVICE RELEASE N63

NATURE OF RELEASE: Exhause pipe lockrings MODELS AFFECTED: All Commando PARTS AFFECTED: Exhaust lockring NM18092 DISTRIBUTION: Worldwide (for General Distribution) EXPLANATION: In cases where slackening of the exhaust lockrings takes place, retightening may not provide a permanent cure. On new motorcycles now leaving the factory, tab washers part number 062412 and lockrings with shorter threads, part number 062464 are fitted for greater security. These tab washers and lockrings can be applied to earlier motorcycles to good effect. The existing lockrings NM18092, which have longer threads can be used with tab washers but the greater clearance will allow the tab washers to move and perhaps chatter. For this reason the new lockrings are recommended. The tab washers have 3 tabs, one to locate between the cylinder head fins and two tabs, one of which locates between the lockring fins.   ACTION: Locate the single tab of the tab washer between the cylinder head fins. Fit the exhaust with lockring and tighten the lockring completely. Run the engine to working temperature and then, using a hammer and suitable drift, tap one of the tabs between the most convenient fins. Unintentional slackening of the lockrings is then impossible. September 1971 Norton Villier Canada Limited