3) Pneumatic Synchronization - Rotax 914 Series Maintenance Manual

4.1.3)
Effectivity 914 Series
Edition 1 / Rev. 1
MAINTENANCE MANUAL
Pneumatic synchronization
See Fig. 26 and 27.
◆ NOTE
Mechanical synchronization has already been carried
out.
◆ NOTE
Not possible with drip tray fitted. If a pneumatic syn-
chronization is absolutely necessary, remove the drip
tray and refit it after adjustment.
The two carburetors are adjusted to equal flow rate at idling with a
suitable flow meter or vacuum gauges (1).
There are two possible connection methods.
Option 1. Remove hex. screw (6) M6 x 6 from the intake manifold(7)
and connect the vacuum gauge(s).
Remove the compensating tube (2) with attached hoses (12) (connec-
tion between intake manifolds) and plug the connections in the intake
manifolds.
Option 2. Remove the compensating tube hose (2) from the push on
connection (5) after removing the tension clamp (4).
Using the push on connection (5), install a flexible rubber hose (8)
leading to the vacuum gauge (1), using the balance tube (4). Install the
other flexable rubber hose leading to the vac gage. See Fig. 26.
Before proceeding any further, secure the aircraft on the ground using
wheel chocks and ropes.
▲ WARNING: Secure and observe the propeller zone during engine
operation.
Start the engine and verify the idle speed. If necessary correct as per
12-00-00, sec. 4.1.2.
If a setting of more than 1/2 turn is required, repeat mechanical
synchronization to prevent too high a load on the idle stops.: If the idle
speed is too high, the maximum the idle screw can be unscrewed is
complete turn.
If no satisfactory result can be achieved, inspect the idle jets for
contamination and clean if necessary
■ CAUTION:
Also check for translucent, jelly-like contamination.
Inspect for free passage.
BRP-Rotax
12-00-00
page 27
Sept. 01/07