CARBURETTERS (1) Top up the piston damper with the recommended engine oil until the level is {r in. above the top of the hollow piston rod. ' SET JET ENGINE SPEED I RESTRICTOR HERE JUST COMMENCIN T0 FALL as NOTEOn dust-proofed carburetters, identied by a transverse hole drilled in the neck of the suction chambers and no vent hole in the damper cap, the oil level must be } in. below the top of the hollow piston rod. ENGINE RPM. _ -4 -3 -2 -1 1 +1 +2+3 +4 JET ADJUSTING NUT-FLATS D 0476 Check the idling speed against the gure given in TUNING DATA, and adjust if necessary by altering both throttle adjusting screws, each by the i ~ same amount. Using the balancing meter, check that the carburetters are balanced. (6) Using the exhaust gas analyser, check that the percentage CO reading is within the limits given in TUNING DATA. If the reading falls outside the limits given, reset 'both jet adjusting nuts by the minimum amount necessary to bring the reading just within the limits. If an adjustment exceeding two ats is required to achieve this the test equipment should be checked for correct calibration. . 1 '00473. (2) Warm up the engine as described in TUNING CONDITIONS. (3) Turn the throttle adjusting screw on both carbu- retters until the idling speed given in TUNING DATA is obtained. (4) Using an approved balancing meter in accordance with the makers instructions, balance the carbu- retters by altering the throttle adjusting screws; the idling speed obtained during this operation must be as given in TUNING DATA. A6332! (5) During the following procedure, just before the readings of the tachometer and exhaust gas analyser are taken, gently tap the neck, of each suction chamber with a light non-metallic, instrument (eg. a screwdriver handle). (7) Hold the jet adjusting nut (l) on each carburetter, Engine Emission. Issue 3. Turn the jet adjusting nut (1) an bath carbu. retters up to weaken, down torlairen; the same amount until the fastest speedyisgraeancled on the tachometer. Turn both adjusting nuts veryzslom up (weaken)- until the engine speed just 001ntan rut, then turn both adjusting nuts one at d0wn (rich). 12383 429 to prevent it turning, and rotate the adjustment restrictor (7) round the nut until the vertical tag contacts the carburetter body on the left-hand side when viewed from the air cleaner ange (see illustration). In this position, bend the small tag on the adjustment restrictor down so that the restrictor locks to the nut and will follow its movements. 4-13