O.S. Engines GGT15 - Manual (Page 2)

138-11 148-10 15x6-8
Use a tank designed for gasoline. (Tanks designed
for glow fuel use a rubber cap which is deteriorated
by gasoline.)
A 200cc tank will provide 12 to 13 minutes flight.(With
full throttle, it will provide 8 to 10 minutes flight.)
Install a commercially available gasoline fuel filter
between fuel tank and carburetor. (Clean the filter
from time to time.)
FUEL TANK & LINES
CARBURETOR PARTS NAME
PROPELLER
The choice of propeller depends on the design and
weight of the aircraft and on the type of flying in which you
will be engaged. Determine the best size and type after
practical experimentation. As s starting point, refer to the
props listed in the table shown below. Slightly larger, or
even slightly smaller props than those shown in the table
may be used, but remember that propeller noise will
increase if blade tip velocity is raised due to high rpm or if
a larger diameter/lower pitch prop is used. Be well aware
that the propeller rotating arc will increase when using a
larger propeller with this engine. Carry out the needle
adjustments only after stopping the engine. Do not allow
your face or hands to come close to the rotating prop.
Type Size (DxP)
Sport/Acro/Scale
Warning:
Make sure that the propeller is well balanced.
An unbalanced propeller and/or spinner can cause
serious vibration which may weaken parts of the
airframe or affect the safety of the radio-control
system. Do not use any propeller which has
become split, cracked or nicked even very slightly,
or received strong impact even if no apparent
damage is visible.
1.
PROPELLER & SPINNER ATTACHMENT
There is a risk, particularly with powerful two-stroke engines,
of the propeller flying off if the prop nut loosens due to
detonation ("knocking") in the combustion chamber when
the engine is operated too lean, or under an excessively
heavy load.
Obviously, this can be very hazardous. To eliminate
such dangers, the O.S. Safety Locknut Assembly was
devised.
Install this as follows:
To be equal
To be equal Ream to 8.1mm dia.
Ream the propeller shaft hole to 8.1mm bore with
an appropriate reamer, checking that the hole is
exactly centered.
Install the prop to the engine shaft, followed by the
retaining washer and prop nut and tighten firmly
with a 14mm wrench. (not supplied).
2.
3. Add the special tapered and slotted locknut and
secure with a 12mm wrench while holding the prop
nut with the 14mm wrench. (not supplied).
Make a habit of always checking the tightness of the
propeller before starting the engine. Remember that,
especially with wooden propellers, there is a
tendency for the material to shrink, or for it to be
reduced by the serrated face of the drive hub.
Retighten the propeller nut if necessary after
loosening the Safety Propeller Locknut. The locknut
should be tightened firmly after retightening the
propeller nut.
NOTE:
Since the GGT15 is intended to be started with an
electric starter, the addition of a spinner assembly for
centering the starter sleeve is desirable.
Special propeller locknut sets are available for use
with spinners. Use a good quality well balanced
spinner, enclosing the propeller boss.
Make sure that it is of precision-made and sturdy
construction so that the spinner shell cannot loosen
when the starter is used.
Make sure the spinner notches do not interfere the
propeller. If they do, cut the notches to clear.
Note:
Some spinners which are retained at the top of the
cone cannot be used with the prop locknut
supplied with the engine. In this case, optional
locknut sets are available from O.S. – Propeller
Locknut Set for Spinner (Code No.45910200 4mm)
and (Code No.45910300 5mm).
MIXING OF OIL
Use regular gasoline. (No need to use high octane
gasoline.)
Alcohol based glow fuel cannot be used in this
engine. Not only will the engine not work properly
but the internal carburetor plastic parts will be
damaged.
Use high quality commercially available 2 stroke
engine oil.
Follow the oil manufacturer’s recommendations
concerning the mixture ratio of gasoline and oil.
If there is no recommendation, mix with a 25~30:1.
We have checked the following oils with the
mixture of 50:1.
KLOTZ ModeLube®
AMSOIL Saber
Zenoah Genuine FC Class
Concerning the mixture ratio for running-in,
follow the instructions in the RUNNING-IN
section.
With a gasoline engine, passages in the carburetor
are narrower than that of a glow engine, and
therefore very sensitive against foreign matter such
as dust. It is suggested to use optional accessory
Super Filter L (Code No. 72403050) when filling a
tank in the model from a container used for
transportation or storing.
Regulator
Use fuel line keepers of stainless wire, etc. at the end
of the tubing to prevent the tubing from coming off.
This engine does not require a muffler pressurized
fuel system but be sure to provide an air vent.
Be sure to use a gasoline
resistant fuel tank cap.
Be sure to equip
air vent pipe.
Be sure to use fuel line keepers of
stainless wire, etc. to prevent tubing
from coming off.
Be sure to replace tubing
inside periodically.
To the fuel
pump inlet
tubing for
re-fuelling
Be sure to install an in-line fuel filter between the
tank and carburetor to prevent foreign matter in the
tank from entering the carburetor. Clean the filter
periodically.
Needle Valve
Mixture Control Valve
Throttle Lever
Fuel Inlet
NEVER disassemble the fuel pump or pressure
regulator. Their original performance may not be
restored after reassembly.
DO NOT allow foreign matter to enter the fuel
system. Dirt inside the pump or regulator, no matter
how small, may obstruct the flow of fuel and prevent
these components from working properly.
CARE OF FUEL PUMP & REGULATOR
DO NOT obstruct the small rectangular hole at the
bottom of the regulator, nor the regulator will not
function correctly.
NEVER insert anything into the inlet or outlet nipples
in an attempt to clear a suspected obstruction.
ALWAYS use fuel filters. Keep the fuel tank
scrupulously clean and filter all fuel as it enters the
tank (e.g.via an O.S.'Super-Filter' Code No.72403050)
and use a good quality in-line filter between the tank
and pump. Remember to inspect filter screens at
regular intervals and rinse clean as necessary.
Rectangular
hole
NEVER use kerosene, thinner or any organic solvent
for cleansing the pump. Rubber parts will be ruined
by these materials. Use only alcohol (methanol) or
gasoline.
THROTTLE LINKAGE
Before connecting the throttle to its servo, make sure
that the throttle arm and linkage safely clear any
adjacent part of the airframe structure, etc., as the
throttle is opened and closed. Connect the linkage so
that the throttle is fully closed when the transmitter
throttle stick and its trim lever are at their lowest
settings and fully open when the throttle stick is in its
fully-open position. Carefully align the appropriate holes
in the throttle arm and servo horn so that they move
symmetrically and smoothly through their full travel.
For plumbing use TYGON F-4040 (Yellow color) or
strong nitrile rubber of more than 2.4-3.2mm ID and
4.8-6.4mm OD. Replace tubing periodically as it
becomes hardened. (Replace tubing inside the fuel
tank every six months.)
The Needle-Valve
For adjusting the mixture strength when the throttle is
fully open Needle-valve adjustment effect the mixture
strength at round mid speed.
The Mixture Control Valve
For adjusting the mixture strength at part-throttle and
idle speed, to obtain steady idling and smooth
acceleration to mid speed.
Two adjustable controls are provided on this
carburetor.
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
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.
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 high speed needle 200 below maximum
rpm. The low speed needle 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.
GLOWPLUG IGNITER
For the plumbing in the fuel tank, we recommend
using O.S. fluororubber tube 2 mm ID x 4 mm OD x
500 mm length (code # 28382100).
A glow plug heater for GGT15 is nothing special.
You can use a conventional glow plug igniter.
You may find the G5 glow plug filament does not
glow as bright as the conventional glow plugs.
But you can start the engine without difficulties since
the flashpoint of gasoline is lower than that of
alcohol based glow fuel.