ADJUSTMENTS

Fig. 1: Throttle valve measurement — 1.2L carbureted engine

Fig. 2: Throttle valve measurement — 1.6L and 1.8L carbureted engines

With the carburetor removed from the engine, set the fast idle cam adjusting lever on the fourth highest step of the fast idle cam.
Check to be sure that the choke valve is fully closed.
Measure the clearance between the lower edge of the primary throttle valve and the bore.
Measurement should be as follows:
- DFC-328: 0.0303 in. (0.77mm)
- DCZ-328: 0.0472–0.0587 in. (1.20–1.49mm)
- DCP-306: 0.0386–0.0528 in. (0.98–1.34mm)
If not within specification, turn the fast idle adjusting screw.

Fig. 3: Using a finger to hold the choke valve closed — 1.2L carbureted engine

Fig. 4: Vacuum break opening angle adjustment — 1.6L and 1.8L carbureted engines

Move the throttle lever while lightly holding the choke valve with your hand, to keep it fully closed. Release your hand to make sure the choke valve is fully closed.
With the choke valve closed, connect a portable vacuum pump to the vacuum break diaphragm and continue to apply vacuum pressure until the diaphragm shaft moves a complete stroke toward the diaphragm.
Measure the clearance (R) while lightly holding the choke valve with your hand. Clearance should be as follows:
- DFC-328: 0.063 in. (1.6mm)
- DCZ-328: 0.059–0.075 in. (1.5–1.9mm)
- DCP-306: 0.059–0.075 in. (1.5–1.9mm)
If not within specification, adjust by bending the pawl at the tip of the lever.

Fig. 5: Float and fuel level adjustment — 1.2L carbureted engine

Fig. 6: Float components

Fig. 7: Float and fuel level adjustment — 1.6L carbureted engine

Fig. 8: Float and fuel level adjustment — 1.8L carbureted engine

The float level may be adjusted with the carburetor installed on the engine, by removing the air horn as follows:

Disconnect the accelerator pump actuating rod from the pump lever.
Remove the throttle return spring.
Disconnect the choke cable from the choke lever, and remove it from the spring hanger.
Remove the spring hanger, the choke bellcrank and the remaining air horn retaining screws.
Lift the air horn slightly, disconnect the choke connecting rod, and remove the air horn.
Invert the air horn (float up), and measure the distance between the surface of the air horn and the float.
Clearance should be as follows:
- DFC-328: 0.437 in. (11.1mm)
- DCZ-328: 0.435–0.492 in. (11.5–12.5mm)
- DCP-306: 0.393 in. (10mm)
If not within specification, bend the float arm until the clearance is correct.
Invert the air horn to its installed position.
On the DCZ-328 and DCP-306 carburetors, measure the distance between the float arm and the needle valve seat. On the DFC-328 carburetor, measure the distance between the choke chamber and the bottom of the float.
Clearance should be as follows:
- DCF-328: 1.835 in. (46.6mm)
- DCZ-328: 0.059–0.075 in. (1.5–1.9mm)
- DCP-306: 0.051–0.067 in. (1.3–1.7mm)
If not within specification, adjust by bending the float stops.

Fig. 9: Measuring throttle valve opening — 1.2L carbureted engine

Fig. 10: Measuring throttle valve opening — 1.6L and 1.8L carbureted engines

With the carburetor removed from the engine, operate the linkage so that the connecting rod contacts the groove on the end of the secondary actuating lever.
Measure the clearance between the lower end of the primary throttle valve and its bore.
Clearance should be as follows:
- DFC-328: 0.236 in. (6.0mm)
- DCZ-328: 0.271–0.275 in. (6.89–6.99mm)
- DCP-306: 0.236 in. (6.0mm)
If not within specification, adjust the clearance by bending the connecting rod.
Check to make sure that the linkage operates smoothly after performing the adjustment.