Norton decompressor arm, side valve c1948+ . Spindle bore: 1/2" (12.6mm); Offset: 1/2 inch (12.6mm) - measured from centre of bolt hole to centre of cable hole); Length: 1 3/4" (45mm) - measured from centre of shaft hole to centre of cable hole). Not all side valves are the same, this arm fits the engines where the spindle points forwards beneath the exhaust port.Original part numberC2/67 - exhaust valve lifter
