1. Remove the air intake manifold.

2. Ensure that the cold start knob is fully in, slacken the cam adjusting screw (4) until it is clear of the cam.

3. Slacken the accelerator cable adjustment (1).

4. Set the butterfly adjusting screws to threads protruding below their retaining bracket.

5. Slacken the locknuts (5) on the three adjusting rods (6).

6. Turn the accelerator cross-shaft until it is held against the backstop. Adjust the vertical link rods until the butterflies are fully open, i.e., horizontal to the air flow (Fig. 6). Tighten the locknuts and allow the butterflies to return to the closed position.

7. Set the accelerator cable (1) to take up free play in the cable without moving the butterflies.

8. Adjust the cold start cable to bring the point of the cam (7) adjacent to the adjusting screw.

9. Turn the air valve screw (2) fully in and slacken off five complete turns.

10. Start the engine and when normal running temperature is reached, place an air flow meter against each air intake in turn (Fig. 7). Turn the butterfly adjusting screw (8) until the butterflies are at the point of closure, with the air flow meter showing a zero reading whilst the full weight of the return spring is taken on the adjusting screw (8) and not on the butterflies.

11. Adjust the air valve screw to give an idling speed of 750 to 800 r.p.m. (Fig. 8).

12. With the engine idling and warm, pull the cold start cable fully open.

Note. This must be done with the cable as pulling the control knob will also increase the quantity of fuel delivered by the metering unit.

13. With the cam turned to its fully opened position, turn the adjusting screw (4) until the engine speed reaches
approximately 1700 r.p.m.

14. Release the cable and tighten the locknut.

15. Adjust the excess fuel lever cable on the metering unit
to give full travel on the lever.

Note. The first movement of the cold start knob must take up the free play on the lever.

16. Replace the air intake manifold.