Maintenance of the Solex 38 PDSI carburetor (BMW 5 Series E12)

Adjusting the air damper drive

Remove the air filter.

After unscrewing screw 1 (see photo), disconnect the air damper control rod.



Adjust the length of the outlet ("A") of the rod casing from the clamp to a value of no more than 15 mm.



Move the choke control lever to the stop, which corresponds to the full opening of the choke, and insert the choke control rod so that the choke control handle has a travel reserve of 2 mm. Tighten screw 1.

Adjusting the starting clearance of the air damper

Set the air damper control lever to position II (see photo), which corresponds to starting a cold engine.



In this position, the air damper should open by 5.3±0.3 mm. Use a drill to check the starting gap "B" of the air damper.





If necessary, adjust the air damper starting gap with screw 2.

Adjusting engine idle speed

Set the engine idle speed to 800±100 rpm and the carbon monoxide (CO) content in the exhaust gases to 1.5% by alternately rotating adjusting screws 1 for the quantity and 2 for the quality (composition) of the mixture.

Adjusting the position of the accelerator pump nozzle

The accelerator pump nozzle is pressed into the carburetor body. Check the direction of the fuel stream coming out of the nozzle, which should hit the top of the diffuser. If necessary, fix the tube in the desired position with glue such as Loctite No.90.

Replacing the needle valve and float

Remove the carburetor cover.

Remove the needle valve.

Remove the float axle stopper, having previously marked its position, and take out the float together with the axle.

Install a new needle valve and float. Reinstall the removed parts in the reverse order of removal.