Adjusting engine idle speed
After completing the preparatory operations (see carburetor Solex Zenith 35/40 INAT) using the adjusting screw 1 (see photo) of the mixture quantity, set the crankshaft speed at idle speed to 900±50 rpm.
Remove the threaded plugs from the exhaust manifolds and screw in the threaded plugs 130 020 instead.
Attach the gas analyzer and use the adjusting screws 2 (see photo) to adjust the quality (composition) of the mixture until the carbon monoxide (CO) content in the exhaust gases is within 1.0±0.5%.
If the idle speed has changed slightly, adjust it with screw 1.
Warning: If the position of the idle mixture quantity adjusting screw 1 is changed, the starting clearances of the air damper must be adjusted.
Checking the functionality of the vacuum shock absorber of the 2nd chamber throttle valve.
Make sure that the air damper moves freely and that the throttle valve of the 2nd chamber is closed.
Start the engine at idle speed. The shock absorber diaphragm should pull lever 3 to the stop (see photo).
Clamp vacuum hose 4 and move the air damper several times.
If lever 3 is pulled all the way to the stop with each movement of the air damper, then the shock absorber diaphragm is in good condition.