CARBURETTERS \\ (4) With the engine stopped, check that the piston falls freely onto the bridge, indicated by a distinct metallic click, when the lifting pin (6) is released. If not refer to CARBURETTER SERVICING. A640l B. (5) Turn the jet adjusting nut (l) to cover the full range of adjustment available within the limits of the restrictor, selecting the setting where maximum speed is recorded on the tachometer consistent with smooth running. (6) Readjust the throttle adjusting screw (5) to give the correct idling speed if necessary. (7) Check, and if necessary adjust, the mixture control wire (8) to give a free movement of approximately fig-in. before it starts to pull on the jet lever (9). (8) Pull the mixture control knob:_until_,the linkage is about to move the carburetter jet. andadjust the fast-idle screw (4) to give the engine fast-idle speed (Tachometer) given in TUNING DAT-29. Engine Emission. Issue 3. 12383 419 TWIN CARBURETTERS D 0474A A twin-carburetter installation 1. Jet adjusting nuts. 4. Fast-idle adjusting screws. 2. Jet locking nuts. 5. Throttle adjusting screws. 3. Piston/suction chambers. 7. Jet adjustment restrictors. NOTEIn no case should thejet adjustment restrictor be removed or repositioned. Only mixture adjustments within the limits of the restrictor are available for tuning. Balancing of twin carburetters must only be carried out with the use of an approved balancing meter. If satisfac- tory adjustment or balancing is not obtainable within the limits of the jet adjustment restrictor, refer to CARBU- RETTER SERVICING. A6395A (1) Top up the piston damper with the recommended engine oil until the level is Q-in. above thetopof the hollow piston rod. 4-3