O.S. Engines GGT15 User Manual

Two stroke glow gasoline

600930400000

It is of vital importance, before attempting to operate your
engine, to read the general 'SAFETY INSTRUCTIONS
AND WARNINGS' in the following section and to strictly
adhere to the advice contained therein.

Also, please study the entire contents of this
instruction manual, so as to familiarize yourself with
the controls and other features of the engine.

engine for airplanes

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

Remember that your engine is not a " toy ", but a
highly efficient internal-combustion machine
whose power is capable of harming you or others,
if it is misused or abused. As owner, you, alone,
are responsible for the safe operation of your
engine, so act with discretion and care at all times.
If at some future date, your O.S. engine is acquired
by another person, we would respectfully request
that these instructions are also passed on to its
new owner.

The advice which follows is grouped under two
headings according to the degree of damage or
danger which might arise through misuse or
neglect.

WARNINGS

These cover events which might involve serious
(in extreme circumstances, even fatal) injury.

NOTES

These cover the many other possibilities, generally
less obvious sources of danger, but which, under
certain circumstances, may also cause damage or
injury.

WARNINGS

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.

Gasoline is poisonous. Do not allow it
come into contact with the eyes or mouth.
Always store it in a clearly marked
container in a cool and dark place and out
of the reach of children. There is a
possibility that it may damage your health.

Gasoline is highly flammable. Keep it away
from an open flame, excessive heat,
sources of sparks, or anything else which
might cause it to ignite. Do not smoke or
allow anyone else to smoke near to it.

ABOUT THE ENGINE

How to adjusting the carburetor of this engine is
completely different from that for the conventional glow
engine’s carburetor. Please study the CARBURETOR
ADJUSTMENT section so as to familiarize yourself
with the controls and other features.

GGT15 is a glow gasoline engine ignited by a glow
plug but using gasoline. So no ignition module and
battery is required.

This engine is designed for experienced fliers.
Beginners and newcomers should not use this engine.

The engine unit, silencer and carburetor are
specially designed.

The normal rotation direction of the engine is
counterclockwise facing to the propeller.

It offers broad power characteristics suitable for
sport flight as well as acro flight.

The large and dense cooling fins ensure sufficient
cooling against overheating.

We apply a “G5” glow plug to GGT15, which is
exclusively developed for Glow Gasoline engines.
Buy only the same glow plug when you replace it to
the new one due to a break or deterioration. The
conventional glow plugs for alcohol based glow
engines such as No.6 (A3), No.7, No.8, No.10 (A5)
are not applicable to GGT15.

The supplied E-4040 silencer develops very efficient
silencing.

STANDARD ACCESSORIES

E-4040 Silencer Assembly

Silencer Retaining Screw
(M4x40 2pcs.)

GGT15

Carry out the mixing of the gasoline and
oil outdoors or in a well ventilated place
away from any source of fire to prevent the
possibility of a fire.

Refill the fuel tank only after the engine is
well cooled down, or there is a danger of
fire.

Go outside and stay away from the
vaporized gasoline when you check the
power distribution of the glow plug attached
to the glow plug igniter by looking at the
filament. Failing to do so may cause fire.

Model engines generate considerable heat.
Do not touch any part of your engine until
it has cooled. Contact with the muffler
(silencer), cylinder head or exhaust header
pipe, in particular, may results in a serious
burn.

Observe the laws and regulations in each
country and district concerning the usage,
transportation and storage of gasoline. Ask
details at the fire station in each district.

Never operate your engine in an enclosed space.
Model engines, like automobile engines, exhaust
deadly carbon-monoxide. Run your engine only
in an open area.

Do not operate the engine nor model alone, or
there is a possibility of injury.

NOTES

Any propeller requires utmost attention to handle.
Be sure to follow the instruction manual supplied with
a propeller.

This engine was designed for model aircraft.
Do not attempt to use it for any other purpose.

Start the engine only after installing it in the model.
Do not start the engine before installing it in the
model, or there is a possibility of injury.

Be sure to use an effective silencer (muffler).
Frequent exposure to an open exhaust may
eventually impair your hearing. Such noise is also
likely to cause annoyance to others over a wide area.

Mount the engine in your model securely, following
the manufacturers’ recommendations.

For their safety, keep all onlookers (especially small
children) well back (at least 10 meters) when
preparing your model for flight.

ENGINE PARTS NAME

E-4040 Silencer

Cylinder Head

Carburetor
Type 61H

Drive Hub

Propeller Washer

Propeller Nut

Crankshaft

Pump Unit PD-08

Lock Nut

Crankcase

Glow Gasoline
Plug G5

Beam Mount

Cover Plate

Install a top-quality propeller of the diameter and
pitch specified for the engine and aircraft.

Discard any propeller which has become split,
cracked, nicked or otherwise rendered unsafe.
Never attempt to repair such a propeller: destroy it.
Do not modify a propeller in any way.

Install the propeller on the shaft so that the curved
face of the blades faces forward – i.e. in the direction
of flight. Firmly tighten the propeller washer and
propeller installing screws using the correct size
wrench. Always check the tightness of propeller
installing screws and retighten them, if necessary,
before starting the engine. Also, check the tightness
of all the screws and nuts before restarting the
engine.

Always check the throttle linkage.If it is disconnected,
throttle action becomes uncontrollable, which may
result in a serious accident.

Take care that loose clothing (ties, shirt sleeves,
scarves, etc.) do not come into contact with the
propeller. Do not carry loose objects (such as
pencils, screwdrivers, etc.) in a shirt pocket from
where they could fall through the propeller arc.

Use an electric starter for this engine. The wearing of
safety glasses is also strongly recommended.
If you try hand starting, be sure to use a chicken stick
or heavy glove. Never attempt to start the engine
with a bare hand.

Be sure to carry out adjustments of the high speed
needle and slow speed needle after stopping the
engine.

Do not start your engine in an area containing loose
gravel or sand. The propeller may throw such
material in your face and eyes and cause injury.

If you have to carry the model to the take-off point
with the engine running, be especially cautious.
Keep the propeller pointed away from you and walk
well clear of spectators.

To stop the engine, fully close the throttle valve via
the transmitter to shut off the fuel supply. Otherwise
there is a possibility of injury.

Do not crank the engine right after the engine is
stopped because the engine may start with a crank
even when the glow plug is not ignited. Failing to do
so may cause injury.

Connect the throttle linkage so that the engine can
be stopped via radio operation.

INSTALLATION

It is suggested to use an engine mount as heavy and
rigid as possible for highest performance and safe
running. Install the engine on a mount using at least
3mm steel screws, such as Allen type, with locknuts,
for bolting the engine to the bearers.

Also, use the Nord Lock Washers (optional extra)
and other anti-loosening washers or apply locking
agent.

Be sure that there is sufficient air intake and outlet
area on the model for engine cooling to avoid
overheating. (Pay careful attention to the cooling
since a gasoline engine generates more heat than an
alcohol based glow engine.)

INSTALLATION OF SILENCER

Secure the silencer to the engine by means of two
retaining screws supplied after the engine is securely
mounted on a model.

The exhaust outlet of the silencer can be rotated by 90
degrees in the following manner.

Loosen the locknut of the silencer and assembly screw.

1.

Set the exhaust outlet at the required position by

2.
rotating the rear part of the silencer.

Re-tighten the assembly screw, followed by the locknut.

3.

It is recommended to seal the fitting faces of engine
exhaust and silencer with liquid gasket. Gasket at the
joint part of the silencer will lose its sealing effect in a
long time running. In this case, replace the gasket or
apply liquid gasket to the joint.

FUEL TANK & LINES

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.)

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.)

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).

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 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.

Be sure to equip
air vent pipe.

To the fuel
pump inlet

tubing for
re-fuelling

CARBURETOR PARTS NAME

Throttle Lever

Mixture Control Valve

Two adjustable controls are provided on this
carburetor.

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.

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.

CARE OF FUEL PUMP & REGULATOR

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.

NEVER insert anything into the inlet or outlet nipples
in an attempt to clear a suspected obstruction.

Be sure to use fuel line keepers of
stainless wire, etc. to prevent tubing
from coming off.

Be sure to replace tubing
inside periodically.

Be sure to use a gasoline
resistant fuel tank cap.

Regulator

Fuel Inlet

Needle Valve

DO NOT obstruct the small rectangular hole at the
bottom of the regulator, nor the regulator will not
function correctly.

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.

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.

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

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.

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:

Ream the propeller shaft hole to 8.1mm bore with

1.
an appropriate reamer, checking that the hole is
exactly centered.

To be equal

Install the prop to the engine shaft, followed by the

2.

retaining washer and prop nut and tighten firmly
with a 14mm wrench. (not supplied).

Add the special tapered and slotted locknut and

3.

secure with a 12mm wrench while holding the prop
nut with the 14mm wrench. (not supplied).

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).

13x8-11 14x8-10 15x6-8

To be equal

Ream to 8.1mm dia.

Rectangular
hole

Size (DxP)

NOTE:
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.

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.

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.

GLOWPLUG IGNITER

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.

RUNNING-IN

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.

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.