Fast idle cam position
1. The gap between the edge of the lowered flap and the wall of the neck (see section 16) must be adjusted correctly.
2. If not already done, remove the suction cover.
3. Open the throttle and then close the choke by lightly pressing the choke lever. Release the throttle.
4. Check that the fast idle adjustment screw is resting on the second highest shoulder of the fast idle cam (see fig. 3.42). If this is not the case, check the correct position of the suction spring and then adjust the position of the screw by bending the lever "2" (see fig. 3.42).
Pic. 3.42. Pierburg carburetor: fast idle cam position adjustment: 1. Fast idle cam; 2. Adjustment lever; 3. Choke control lever (press it in the direction indicated by the arrow); 4. Fast idle speed adjustment screw.
5. Reinstall and secure the suction cover, aligning the installation marks.
Throttle clearance at fast idle
6. Set the fast idle adjustment screw to the highest cam shoulder.
7. Using a drill or calibration rod of the required diameter, measure the gap between the primary throttle valve and the thrust screw. If necessary, adjust the clearance using the fast idle screw. (This is a preliminary adjustment. Final adjustment is made with the engine running).
Accelerator pump supply
8. During this test, you will need to manually feed fuel into the float chamber (take the necessary fire safety measures).
9. Place the primary chamber over the measuring cup. Fully open and close the throttle valve 10 times (1 second to open, pause 3 seconds after each closing). Check that the fast idle cam does not limit the throttle travel.
10. Measure the volume of fuel supplied and divide it by 10 to determine the pump flow per piston stroke. Compare the resulting value with the Specifications.
11. If adjustment is necessary, loosen the clamping screw and rotate the cam plate in the desired direction (see photo). Tighten the clamping screw and check the pump flow again.
Photo 11/19. Adjusting the accelerator pump flow ("+" — increase, — decrease).
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