O.S. Engines GF30 - Manual (Page 3)

Use a fuel with increased oil content and set the
needle a little on the rich side. Too rich a needle
setting may cause misfiring or erratic running due to
fouling of the plug.
Use a 25:1 fuel/oil mixture if the particular brand of
oil states 50:1 mix. Use a 20:1 fuel/oil mixture if the
particular brand of oil states 25:1 mix. Set only the
needle valve 200 below maximum rpm. The mixture
control valve need not be richened.
No need to carry out running-in on a bench nor with
the model fixed. Just fly the model with the above
mentioned fuel and needle setting.
A total of 10 flights (2 litters fuel) are required.
Avoid prolonged full throttle running at initial stage,
and gradually extend the full throttle running time.
RUNNING-IN
WARNING:
When ground running the engine, avoid dusty or
sandy locations. If dust or grit is drawn into the
engine, this can have a ruinous effect, drastically
shortening engine life in a matter of minutes.
Open the needle-valve 2.5 to 3 turns from the fully
closed position. (Mixture control valve is pre-set at
nearly best position when the engine leaves the
factory.Therefore, do not adjust the mixture control
valve at this point.)
Turn the transmitter switch ON.
Turn the receiver switch ON.
Turn the igniter switch OFF.
Set the throttle at half opened position.
Draw the fuel to the carburetor by turning the
engine for 7 to 8 seconds with an electric starter.
Set the throttle at 1/8 open from the fully closed
position.
Turn the igniter switch ON.
Tell the helper and onlookers that you will start the
engine now and have the helper hold the model
securely.
Apply an electric starter to start the engine.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
STARTING
The GF30 cannot be started by flipping a propeller.
Be use to use an electric starter to start the engine.
The GF30 is not equipped with a choke valve.
Draw the fuel to the carburetor by an electric starter.
Although the carburetor’s appearance and construction
resemble conventional glow engine’s carburetor, how
to adjust is completely different from that for glow
engine‘s carburetor. Please study the following
instructions so as to familiarize yourself with the
controls and other features of the engine.
CARBURETOR ADJUSTMENT
1. Before attempting to operate your engine
It is expected the engine runs a little unstably
(uneven RPM and light breathing) until the inside
parts of the carburetor get used to the fuel (around
when the running-in is completed) but the engine
won’t quit. Run the engine as it is. Also, for about 10
seconds after the first starting of the day, it is
expected the engine runs unstably but the engine
won’t quit. Run the engine as it is.
2. Key points for adjustments
Mixture control valve is pre-set at nearly best
position when the engine leaves the factory.
Therefore, it is not necessary to adjust the mixture
control valve until running-in is completed.
Adjust the needle-valve only.
1)
With a conventional glow engine, the needle-valve
is gradually closed from the rich mixture. On the
contrary, with the GF30, the needle-valve is
opened from the lean mixture. Please fully note
this difference.
2)
3. Adjustments
1) Needle-valve adjustment
Open the throttle fully gradually when the engine is
started.
Close the needle-valve and the engine RPM
increase. (Close the needle-valve at a pace of
30~45 degrees/second smoothly.)
When the needle-valve is closed further, engine
RPM stop increasing and then RPM start decreasing.
Close the needle-valve 60 to 90 degrees further from
the point where RPM start decreasing.
1.
2.
3.
Then, open the needle-valve rather slowly (at a
pace of 15 degrees/second) and the engine RPM
increase.
4.
Open the needle-valve 60-90 degrees further from
the point where maximum RPM are obtained. This
is the nearly best needle-valve position.
5.
Fly the model with this needle-valve position until
running-in is completed (10 full tank or 2 liters
flights). Please observe the general precautions
during running-in such as to avoid prolonged full
throttle running and increase load gradually.
2) Mixture control valve adjustment
1.
2.
3.
4.
5.
6.
7.
8.
Hereafter adjust the needle-valve and/or mixture control
valve if required according to the flight conditions.
Please note with this carburetor, needle-valve adjustment
does not effect the mixture control valve adjustment but
the mixture control valve adjustment effects the
needle-valve adjustment. Therefore, it is required to
adjust also the needle-valve when the mixture control
valve is adjusted.
Mixture Control Valve
Carburetor Body
REALIGNMENT OF MIXTURE CONTROL VALVE
In the course of making carburetor adjustments, it is just
possible that the Mixture Control Valve may be inadvertently
screwed in or out too far and thereby moved beyond its
effective adjustment range.
Rotate the Mixture Control
Valve until its slotted head
is flush with the carburetor
body. This is the standard
position.
Note
Generally, a gasoline engine is sensitive to a lean
mixture compared with a glow engine, and will
stop without warning hesitation and stops with
overheating.
It is recommended that the engine be run with a
slightly richer mixture.
VALVE ADJUSTING
Valve clearances are correctly set before any O.S.
engine leaves the factory and, in normal use, will
seldom require adjustment. However, if, after a
considerable amount of running time, a loss of power
is detected, or if he engine has been disassembled for
repair, these clearances should be checked and reset
as necessary. Clearance should be 0.04mm - 0.1mm
(.0015" - .004") For checking and adjusting the valve
clearances, a VALVE ADJUSTING TOOL KIT is
available as an optional accessory.
Also, a 5.5mm wrench (not supplied) is required
for this purpose.
• Feeler gauge 0.04mm
The kit comes in a plastic case and includes:
(Code No.72200060)
• Feeler gauge 0.1mm
• Hex. key 1.5mm • Wrench 5mm
• Wrench 5.5mm
When the engine is started, make sure the radio
control system works normally (distance test).
Engine does not run erratic with full throttle.
Idling is stable.
Responds positively to the throttle operation.
Warm-up is finished.
FLIGHT & MAINTENANCE
Checking prior to flight
Warm-up is required as with full size aircraft and car
engines. Take off the model after warming the engine
for approx. 10 seconds with full throttle.
Precautions in flight
A slight engine rpm increase and decrease delay is
normal. Abrupt throttle operation will the cause
engine to quit. Move throttle smoothly.
Cooling is more vitally important to a gasoline engine
than to a glow engine. If overheating symptoms (loss
of power at full throttle or exhaust note at mid speed
changes from cloudy one to clear one) are observed
during flight, immediately stop flying and carry out
the following countermeasures.
Enlarge the air intake cutout on the cowling.
Enlarge the air outlet cutout on the cowling. (It is
vitally important.)
Partly cover the air intake cutout on the cowling
where air does not hit direct the engine.
Install an air guiding plate on the fuselage and
cowling so that cooling air may be guided to the
cylinder portion of the engine and muffler.
When the interval between the flights is short and
the engine is still hot, it may be possible overheating
symptoms are observed by circulating the head from
the former flight through the engine even if the
overheating symptoms were not observed during
the former flight. In this case, leave it until the
engine is fully cooled down (in hot weather, it may
take more than one hour.) or run the engine for 4 to
5 minutes at idle.
1)
2)
3)
4)
Maintenance after the day’s flights
Please pay attention to the matter described below
to ensure that your engine serves you well in
regard to performance, reliability and long life.
Check the tightening of each screw, especially
engine installation screws and silencer installation
screws each time. Also, for the first several flights,
tighten the screws after each flight.
As previously mentioned, it is vitally important to
avoid operating the engine in conditions where dust,
distributed by the propeller, may be deposited on the
engine and enter its working parts.
Remember to keep your fuel container closed to
prevent foreign matter from contaminating the fuel.
Install a fuel filter to prevent foreign matter in the fuel
container from entering the fuel tank. O.S. Super
Filter (L) is available as an optional extra.
Install an in-line fuel filter between the tank and
carburetor to prevent foreign matter in the tank from
entering the carburetor.
Clean these filters periodically.
If these precautions are neglected, restrictions of
fuel flow may cause the engine to cut out, or the
fuel/air mixture to become too lean causing the
engine to overheat.
With a gasoline engine rust hardly occurs. Check
the exterior to make sure there is nothing wrong and
wipe off any oil res.
Fig.1
Make sure the mixture control valve is at the factory
setting. (see Fig.1)
After starting the engine, open the throttle fully for 5
to 6 seconds to warm up the engine, and adjust the
main needle as previously shown.
Set the idling at around 2,000 rpm with the throttle
trim on the transmitter.
Move the throttle stick from the idling to the fully
open position several times repeatedly, and measure
the idling rpm with a tachometer. In case idling is
unstable and the rpm decrease gradually in 20
seconds at the idling position, the mixture control
valve is set rich. On the other hand, the mixture
control valve is set lean if the rpm increases at the
idling position, or the engine doesn’t respond quickly
to reduce the rpm at around 2,000 rpm when the
throttle stick is moved from the fully open position to
the idling position.
Stop the engine. If the adjustment is rich, turn the
mixture control valve clockwise 30 degrees at
maximum per each adjustment. If the adjustment is
lean, turn the mixture control valve counter-clockwise.
Each adjustment should be within 30 degree needle
turn.
Repeat the procedures 2 – 5 until the idling rpm
becomes stable. After deciding the mixture control
valve adjustment, determine the final main needle
adjustment.
Set the idling rpm with the throttle trim on the
transmitter at the optimal position depending on the
propeller size and the airplane model.
The engine is almost ideally adjusted if the engine
accelerates smoothly from idling to full throttle even
you move the throttle stick quicker and slower.
Move the throttle stick quickly to full throttle. In case
the engine hesitates before picking up speed or
even ceases firing, the mixture control valve is set
lean. Stop the engine and open the mixture control
valve 15 degrees counter-clockwise.
Move the throttle stick slowly to fully throttle. In case
the engine responds sluggishly to increase rpm, or
the idling rpm is unstable, the mixture control valve
is set rich. Stop the engine and close the mixture
control valve 15 degrees.
Whenever the mixture control valve is readjusted,
the main needle should be readjusted.