O.S. Engines 160FX Ring - Manual (Page 10)

15 ✕ 12
~
14, 16 ✕ 10
~
14,
16.5 ✕ 10
~
13
17 ✕ 10
~
13, 18 ✕ 10
~
12
PROPELLER
The suitability of the prop depends on the size and weight of
the model and type of flying. Determine the best size and type
after the engine has been run in. Check the balance of the
propeller before installing on the engine. Unbalanced
propellers cause vibration and loss of power. Wooden
propellers are to be preferred. Some nylon propellers are not
strong enough to withstand the high power output of these
engines and a thrown blade can be very dangerous.
MIXTURE CONTROLS
Never touch, or allow any object to come into
contact with, the rotating propeller and do not
crouch over the engine when it is running.
The Needle Valve
When set to produce maximum
power at full throttle, this
establishes the basic fuel/air
mixture strength. The correct
mixture is then maintained by the
carburettor's built-in automatic
mixture control system to cover
the engine's requirements at
reduced throttle settings.
Two mixture controls are provided on these engines.
Sport Aerobatic
•
The Mixture Control Valve (carburettor)
This meters fuel flow at part-throttle and idling speeds to
ensure reliable operation as the throttle is opened and
closed. The Mixture Control Valve is factory set for the
approximate best result. First run the engine as received
and readjust the Mixture Control Screw only if necessary.
•
Throttle Lever
Mixtire Control Screw
STARTING
Install an appropriate propeller and tighten securely.
Ream the propeller boss to 9.6mm bore, then check that
the propeller is accurately balanced.
To facilitate electric starting, fit an spinner for centring the
rubber drive insert of the starter.
First tighten 17mm nut securely with a wrench, then tighten
14mm nut securely. Alternatively, a good quality spinner,
enclosing the propeller boss, may be used, but make sure
that it is of precision-made and sturdy construction so that
the spinner shell cannot loosen when the starter is used.
Close the throttle.
Fill the fuel tank. Do not allow fuel to overflow into the
silencer, otherwise the engine may become flooded and
difficult to start.
Check that the needle-valve is closed. (Do not overtighten.)
Now open the needle-valve 2-2 turns from the fully closed
position and temporarily set the throttle in the fully open
position.
2
1
1.
2.
3.
4.
Turn needle-valve clockwise to close
(for leaner mixture)
Turn needle-valve counter-clockwise to
open (for richer mixture)
Mark
Close
Open
9