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## Carburetor Synchronization 

For smooth idling, synchronization of the throttle valves is necessary. When synchronizing, slacken both Bowden cables, and detach the resonator hose (3) of the compensating tube (2) to separate the two air intake systems. [Figure 11-26]  In this condition, no significant difference in the engine running should be noticeable. If adjustment is needed for synchronous basic throttle adjustments (mechanical synchronization), proceed as follows.  [Figures 11-27 and  11-28] 

Adjust the two Bowden cables for simultaneous opening of the throttle valves. Remove the cable fixation (4) on the 

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throttle lever (1). Next, release the return spring (5) from its attachment on the throttle lever (1), and return the throttle lever (1) to its idle stop position (3) by hand. There should be no resistance during this procedure. Unscrew the idle speed adjustment screw (2) until it is free of the stop. Insert a 0.1 mm (0.004 in) feeler gauge (gap X) between the idle speed adjustment screw (2) and the carburetor idle stop (3), then gently turn the idle screw clockwise until contact is made with the 0.1 mm (0.004 in) feeler gauge. Pull out the feeler gauge and turn each idle speed adjustment screw (2) 1.5 turns in clockwise direction. Gently turn each idle mixture screw (6) clockwise until it is fully inserted and, then, open by 1½ turns counterclockwise. Hook the return spring (5) back up to the throttle lever (1) in its original position. Check that the throttle valve opens fully, automatically. Carry out the above procedure on both carburetors. 

NOTE: The mechanical carburetor synchronization is sufficiently exact. 

At this point, place the throttle lever in the flightdeck to the idle stop position. Ensure that the throttle lever remains in this position during the next steps of the synchronization process. With the throttle lever in the idle stop position, move the throttle lever (1) to the carburetor idle stop position, using the cable fixation (4), and secure the Bowden cable accordingly. As soon as the two carburetor Bowden cables are installed (throttle lever idle position), check that the idle speed adjustment screw (2) rests fully on the idle stop (3) without pressure. 

