CARBURETTERS (22) Ret the spring to .the jet needle assembly, ensuring that it locates completely in the groove of the needle support. (23) IMPORTANT. Spring-loaded needles are supplied complete with shouldered spring seats; no attempt should be made to alter the position of the spring seat or convert a xed-type needle to spring loaded application. The raised pip formed in the needle guide ensures that the needle is correctly central.- ized. Under no circumstances must the pip be removed or repositioned. Fit the needle assembly into its guide and t the assembly into the piston. The lower edge of the guide (76) must be ush with the face of the piston and the guide positioned so that the etched locating mark (77) on its lower face is adjacent to and in line with the midway point between the two piston transfer holes as illustrated. Alternative needle guides have a at machined on the guide which must be positioned so that the guide locking screw tightens down onto the at. If the guide is incorrectly positioned so that the locking screw has not tightened down on the at, the head of the screw will protrude from the piston. Engine Emission Issue 4. 18959 425 (24) Fit'a;..new guide locking screw. NOTEGuide locking-screws for spring-loaded needles are shorter than therneedle locking screws used with xed needles. (25) Check'the piston key for security in the carburetter body. Ret the piston assembly to the body and place the piston spring over the piston rod. .(26) Fit the suction chamber and retaining screws, taking care not to wind up the spring; tighten the securing screws evenly. Carburettersall types (27) Ret the damper and washer. (28) Reassemble the pick-up lever, cam lever, cam lever spring, skid washer, and pivot bolt tube or tubes in the positions noted on dismantling. (29) Place the pick-up lever return spring in position over its boss and secure the lever assembly to the carburetter body with the pivot bolt. Ensure that the double-coil spring washer or spacer ts over the projecting end of the pivot-bolt tube. (30) Register the angled end of the return spring-gin the groove in the pick-up lever, and hook the other end of the spring around the moulded peg on the carburetter body. (31) Fit the brass ferrule to the hole in the end of the pick-up link. Relieve the tension of the return spring and t the link to the jet with its retaining screw. When nally tightening the screw, support the moulded end of the jet. ' (32) Without removing the suction chamber, screw the jet adjusting nut until the top face of the jet is ush with the bridge of the carburetter. (33) Turn down the jet adjusting nut to the initial jet setting given in TUNING DATA. (34) Ret the carburetter(s) to the engine, following the instructions given in the relevant vehicle Workshop Manual. Tune the carburetters in accordance with the instructions given in CARBURETTER TUNING -COMPLETE.