Described in this article is how to tune a Weber carburettor used in the ID/DS after 1972.

This carburettor can be recognized by looking at the choke flap. It only covers one barrel (the primary barrel). Furthermore it can be identified by an extra air adjustment screw at the bottom of the primary barrel (see photograph), and a locked secondary spindle adjustment screw (locked with a nut instead of a spring).


    Weber carburettor after 1972
  1. Air adjustment screw
  2. Spindle adjustment screw primary barrel
  3. Spindle adjustment screw secondary barrel
  4. Mixture adjustment screw

NOTE: This procedure is applicable to manual gear box models.


Before starting adjusting the carburettor, make sure the following conditions are met;

The basic adjustments.

Adjustments of the primary and secondary spindle.

Basically it is not allowed to adjust the primary and secondary spindle adjusting screws for this type of carburettor because they are fixed in a certain possition in the factory. However the changes are high that somebody adjusted them anyway in the past, therefor the following setting will enable you to start the engine to tune the carburettor.

Adjusting by hand.

  1. Turn the Air adjustment screw (1) until the car runs at 650 +/- 25 RPM.
  2. Turn the mixture screw (4) until the engine runs at a maximum RPM. Turn this screw inward until the engine starts to run worse.
  3. Repeat step 1 and 2 until the engine runs at a stationarry 650 +/- 25 RPM. Take care that the last step is always step 2.

Adjusting with a CO, CO2 meter.

If you have access to a CO/CO2 meter then adjust the carburettor untill it matches the following table (with a temperature between 15 and 30 degrees).

Type CO CO2
DX-DJ-DJF 2 - 3.6% above 8%
DP-DY-DT-DV-DLF 1.8-3.6% above 8.7%