O.S. Engines FS-91 II FI - Manual (Page 19)

19
FLIGHT ADJUSTMENT
The next step is to take the airplane on an actual flight. Although the adjustments have been
already made, recheck the Limit setting.
Put the throttle stick in the slow position and after starting the engine and allowing it to warm up,
check the stability of engine speed in the slow position (by confirming that the engine does not
stall) and try flying the airplane.
After taking off, fly level for several minutes. Next, repeat flying level in a straight line at full speed.
(This is one way to check the difference in engine speeds when on the ground and in flight.) If it
appears that engine speed fluctuates with much smoke while flying straight, this indicates that
excessive fuel is being supplied to the engine. Turn the injection trim adjustment dial (spare
channel dial) in the (-) lean direction (right) by about 10˚ (about 2 clicks) with the throttle stick in the
full high position. Then repeat flying straight in the same manner as before. Repeat this
adjustment procedure until engine speed has stabilized. (The engine speed will not change
immediately after the air-fuel mixture has been changed. Fly the airplane straight several times to
confirm that engine speed has become stable.) When flying straight as described above, fly both
into the wind and with the wind. Adjustment is completed when there are no disturbances in
engine speed when flying level.
If the engine produces a higher pitch sound immediately after taking off or if the engine appears to
lose power and exhaust cannot be seen at all (although varying somewhat depending on the fuel),
turn the injection trim adjustment dial (spare channel dial) in the (+) rich direction (left) by about 45˚
with the throttle stick in the full high position and reconfirm engine operation by continuing to fly for
3-4 minutes. (When this is difficult to evaluate, land the airplane and recheck engine speed with
the throttle stick in the center and full high positions.) When there is still no change even when the
above adjustment has been made, land the airplane and try readjusting from the first step of the
adjustment procedure. This completes the adjustment procedure.
NOTE:
Repeat this procedure when changing propeller or fuel.
Torgne Roll maneurre increases engine temperature. Cool the engine with level flight.