Bing Constant Depression Carburetor: Check And Maintenance; 1) Leakage Test Of Float Needle Valve - Rotax 912 Series Maintenance Manual

13.1.2)
00326
fig. 037
Effectivity: 912 Series
AIRCRAFT ENGINES
MAINTENANCE MANUAL II

BING constant depression carburetor: Check and maintenance

See fig. 037 and 038
CAUTION: In principle no modification must be made on the
carburetor calibration. The determination of the main jet
is carried out on a dyno at 300 m (1000 ft) above Mean
Sea Level. Modification is allowed to be carried out to our
specifications only by aeronautical personnel or
authorized test staff.
Before removal of the carburetors for a precise inspection, close the fuel
cock and remove the fuel feed lines, collect possibly emerging fuel and
ensure proper disposal.
CAUTION: To avoid contamination in the fuel system proceed with
great care and cleanliness. Put carburetor and parts
removed on a clean surface.
Remove carburetor from the carburetor flange, after loosening the tube
clamps and deposit them on a clean surface.

13.1.2.1) Leakage test of float needle valve

Unhook spring Q from choke lever W and chamber top E.
Connect vacuum pump R to the fuel supply line T and
generate a depression of approx. 0,4 bar (5,8 psi). The depres-
sion must not change within approx. 5 seconds. Otherwise tilt
spring clip Y backward, remove the float chamber U and the
pin I with a punch and remove the float bracket O. Check the
float needle P and its seat for wear and if inlet is contaminated.
With this check the float needle seat is checked for tightness.
If the depression is not maintained, pay particular attention
during disassembly to the float needle with Viton tip and the
carburetor housing.
x 0,1
bar
00026
Initial issue, Jan. 01/2002
fig. 038
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