O.S. Engines GGT15 - Manual (Page 3)

Although the carburetor’s appearance and construction
resemble conventional glow engine’s carburetor, how
to adjusting 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.
Note
Generally, a gasoline engine is sensitive to a lean
mixture compared with an alcohol based 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.
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 with 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 cause the
engine to quit. Move throttle smoothly.
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.
Cooling is more vitally important to a gasoline engine
than to an alcohol based 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)
Fill the carburetor with fuel at the conclusion of a
day's flying. (Pay careful attention to fire and ignition
source when carrying and storing the model.)
If the engine is stored without filling the carburetor
with fuel the inside parts will dry out and not work
properly at the next running. If the engine quits out
of fuel, refill the carburetor with fuel.
When the engine is not to be used for a long period
(more than a year), remove the engine from the
model, clean the outside then remove the
carburetor, and plug all tubing. Clean inside the
engine by rotating the crankshaft with the engine
immersed in container filled with gasoline.
Also use gasoline to clean the outside of the
carburetor. Clean the outside only because the
inside parts are sensitive to foreign substances.
After cleaning the engine, dry it well then inject a
small quantity of oil used to mix fuel and rotate the
crankshaft several times to distribute the oil well
inside the engine. Finally reassemble the engine
and store it in a dry place after inserting it in a heavy
vinyl bag.
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.
O.S. GENUINE PARTS & ACCESSORIES
(72403050)
(79870040)
(55500003)
(71531010)
SUPER FILTER (L)
M4
BLIND NUT (10pcs.)
LOCK WASHER (10sets)
M4
NON-BUBBLE WEIGHT
(S)
(72403051)
SUPER FILTER (S) PROPELLER LOCKNUT
SET FOR SPINNER
5/16"-M5
(45910200)
(45910300)
5/16"-M4
The specifications are subject to alteration for improvement
without notice.
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 the near-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 GGT15, the needle-valve is
opened from the lean mixture. Please fully note
this difference.
2)
3. Adjustments
1) Needle-valve adjustment
Gradually open the throttle fully 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.
Open the needle-valve 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) Adjustment after running-in
Open the mixture control valve 60 degrees from
the original position (factory setting).
Start the engine.
Open the throttle fully 10 seconds to warm the
engine up.
Close the throttle fully.
Set the idling RPM at round 3,000 with the throttle
trim on the transmitter.
Stop the engine.
Close the mixture control valve 15 degrees.
Start the engine and write down the idling RPM.
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.
3) Initial mixture control valve position
1.
2.
3.
4.
5.
While the mixture control valve is set at the near-best
position when the engine leaves the factory, it is
possible you lost the initial position in repeating the
mixture control valve adjustment.
How to reset the initial mixture control valve position is
as follows. Please note this work is very sensitive.
Carry out the work very carefully.
Open the mixture control valve one turn (360
degrees).
Repeat opening the throttle fully and closing the
throttle fully a few times to make sure there is no
resistance during throttle movement.
Close the mixture control valve 30 degrees.
Repeat 2. and 3. until resistance is felt when
opening the throttle from fully closed position.
Open the mixture control valve approx. 90 degrees
from this point. This is the initial mixture control
valve position.
Then, open the needle-valve rather slowly (at a
pace of 15 degrees/second) and the engine RPM
increase.
4.
(27426010) E-4051 SILENCER ASSEMBLY
GLOW GASOLINE ENGINE PLUG G5 (71655001)
(28382100) ID. 2mm × OD. 4mm Length 500mm
(28382200) ID. 3mm × OD. 5mm Length 500mm
FLUORORUBBER TUBE
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.)
Set the throttle at 1/3 open from the fully closed
position.
Tell the helper and onlookers that you will start the
engine now and have the helper hold the model
securely.
Connect a glow plug igniter or battery leads to the
glow plug.
Apply an electric starter to start the engine.
1.
2.
3.
4.
STARTING
The GGT15 cannot be started by flipping a propeller.
Be use to use an electric starter to start the engine.
The GGT15 is not equipped with a choke valve.
Draw the fuel to the carburetor by an electric starter.
NOTE:
Repeat 6 to 8. 9. The position where 90 degrees
opened position from maximum idling RMP is
obtained is the optimum mixture control valve
position. Warning! Never adjust the mixture control
valve while running the engine.
Readjust the needle-valve according to 3. (1)
described above.
Now the adjustment on the ground is completed.
9.
10.
11.
It may be difficult to start the engine when air
temperature is below 10 degrees Celsius. In this
case, keep running the electric starter for around
10 seconds even the engine starts firing.
5.