O.S. engine MAX-55HZ HYPER Setup guide

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.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S.ENGINE
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
NOTES
These cover events which might involve serious
(in extreme circumstances, even fatal) injury.
These cover the many other possibilities, generally less
obvious sources of danger, but which, under certain
circumstances, may also cause damage or injury.
WARNINGS
ENGINE PARTS NAME
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. 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.
NOTES
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.
Never touch, or allow any object to come
into contact with, the rotating parts.
Model engine fuel is also highly flammable.
Keep it away from open flame, excessive
heat, sources of sparks, or anything else
which might ignite it. Do not smoke or allow
anyone else to smoke, near to it.
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
result in a serious burn.
Model engine fuel is poisonous. Do not
allow it to come into contact with the eyes
or mouth. Always store it in a clearly marked
container and out of the reach of children.
This engine was designed for model helicopters.
Do not attempt to use it for any other purpose.
Mount the engine in your model securely, following
the manufacturers' recommendations, using appropriate
screws and locknuts.
Install an effective silencer (muffler). Frequent close
exposure to a noisy exhaust (especially in the case of
the more powerful high-speed engines) may eventually
impair your hearing and such noise is also likely to
cause annoyance to others over a wide area.
Check the linkage to the throttle arm before each flight.
After starting the engine, carry out any needle-valve
readjustments after stopping the rotor by closing the
throttle to the lowest r.p.m.. Stop the engine before
attempting to make other adjustments to the carburetor.
Use an electric starter. The wearing of safety glasses
is also strongly recommended.
Press the rotor head down securely.
Take care that the glow plug clip or battery leads do
not come into contact with rotating parts.
Adjust the throttle linkage so that the engine stops
when the throttle stick and trim lever on the
transmitter are fully retarded. Alternatively, the
engine may be stopped by cutting off the fuel supply.
Never try to stop the engine physically.
Take care that loose clothing (ties, shirt sleeves,
scarves etc.) do not come into contact with the rotor.
Do not carry loose objects (such as pencils, screwdriv-
ers, etc.) in a shirt pocket from where they could fall
through the rotor disc.
For their safety, keep all onlookers (especially small
children) well back (at least 20 feet or 6 metres) when
preparing your model for flight. If you have to carry the
model to the take-off point with the engine running, be
especially cautious. Hold the rotor securely and keep
well clear of spectators.
Warning! lmmediately after a glowplug-ignition
engine has been run and is still warm, conditions
sometimes exist whereby it is just possible for the
engine to restart when turned over WITHOUT the
glowplug battery being reconnected. Remember this
if you wish to avoid the risk of accidents.
Linking the throttle servo to the carburetor
Link the throttle servo to the carburetor using
the throttle lever supplied. Throttle control rod
A and B should be equal length. Set the
linkage so that the servo output lever and
throttle lever are parallel when the throttle
stick on the transmitter is at middle position.
Installing hole intervals on the F lever and on
the J lever are different. Decide the lever to
use according to the servo used. Be sure to
cut off another lever to avoid any interference.
INTRODUCTION
600928500000
Note on heating the glow plug
Example
The heatsink head on the engine is treated with
an anodized finish which does not conduct
current. Therefore, when heating a glow plug,
connect one lead to the glow plug and the other
to the head or cover plate retaining screw.
Avoid sudden high r.p.m. immediately after the
engine is started, as the clutch will engage and you
may be struck by the rotor.
Heatsink Head
Carburetor
Typr 40L
Crankshaft
Propeller nut
Crankcase
Glowplug
Beam Mount
High Speed
Needle Valve
Fuel Inlet
Mixture Control Valve
Throttle Lever
Idle Mixture Control Screw
Mixture Control
Valve Stopper
Thrust Washer
Carburetor Rubber Gasket
Medium Speed
Needle Valve
Cover Plate
STANDARD ACCESSOIES
Glow Plug No.8
This is a high performance engine expressly
designed for 50 size helicopters. Since engine
mounting and muffler mounting bolt patterns are
the same as the 50SX-H Hyper, it can be installed
in the existing 50 size helicopters.
Newly designed 40L carburetor enables to adjust
idling, hovering and high speed independently.
Close to 60 size power offers wide power range
suitable for sport flight as well as 3D flight.
When the governor function from Futaba GY-701 or
GY-750 gyro is employed, the Futaba BPS-1 Back
Plate Sensor can be installed in a cell on the back
plate. By employing the governor function, more
stable flight can be achieved.
The engine mounting bolt hole size of the 55HZ
Hyper is 3.7mm the same as that for the 50SXH
Hyper. Use 3mm Allen type screws for securing
the engine to the engine mounts.
Note on engine installation
Notes on installing cooling fan and clutch
Do not use a tool which
locks piston when installing
a cooling-fan and clutch, or
top of the piston may be
damaged. Also, do not insert
a screw driver or the similar
into the exhaust port.
Do not grip the engine mounting beams with a
vise, or the crankcase will be distorted which
will result in engine breaking.
Vise
NOTES WHEN APPLYING AN ELECTRIC STARTER
Because of this initial tightness, a standard
electric starter may have difficulty in rotating the
engine when cold, before it has been adequately
run-in. In this case, use a high-torque type starter.
Do not over-prime. This could cause a hydraulic
lock and damage the engine on application of the
electric starter.
If over-primed, remove glowplug, close needle-valve
and apply starter to pump out surplus fuel. Cover
the head with a rag to prevent pumped out fuel
from getting into your eyes.
Beam Mount
It is recommended to use
Crankshaft Clamp 3246
(CodeNo.71530400) available
as an optional tool.
As delivered, the engine has the carburetor
lightly fit into the intake. Secure it changing
the angle according to the model.
NOTE
MAX-55HZ Hyper
F
J J
F
28
34
27
33
A
B
90°
90°
A=B

Items necessary for starting
Tools, accessories, etc.The following items are necessary
for operating the engine.
BEFORE STARTING
Fuel
INSTALLATION OF THE ENGINE
Make sure that only the under-surfaces
of the engine’s mounting lugs are in
contact with the engine mount.
INSTALLING THE GLOWPLUG
Install washer on glowplug and insert carefully into
Heatsink-head, making sure that it is not cross-threaded
before tightening firmly.
INSTALLATION OF THE CARBURETOR
CARBURETOR CONTROLS
The under-surfaces of all O.S. engine beam mounting
lugs are precision machined flat and exactyly parallel
to the engine's horizontal axis. It is essential that the
engine mounts in the model are also accurately made
and aligned. If they are not, they will cause stress and
distortion within the engine itself, probably resulting in
loss of performance and internal damage.
The recommended screws for securing the engine to
the engine mounts in the model are 3mm or 4-40 steel
Allen type. It is also advisable to use lock washers or
LOCTITE to prevent nuts from loosening.
Select, by practical tests, the most suitable fuel from
among the best quality fuels available in your country
for helicopter use. For the best throttle response, a fuel
containing 10% to 30% nitromethane is preferable.
Lubricants may be either castor-oil or a suitable
synthetic oil (or. a blend of both) provided that they are
always of top quality. For consistent performance and
long engine life, it is essential to use fuel containing AT
LEAST 18% lubricant by volume. Some fuels
containing coloring additives tend to deterriorate and
may adversely affect running qualities. If in doubt
compare to a fuel known to be good.
Retainer screw
Carburetor Rubber Gasket
0.2mm gap
As delivered, the engine has its carburetor lightly
fitted into its intake boss. Secure it as follows.
With a fixed-wing model, power failure is rarely a
serious threat to the safety of the aircraft since it can
usually glide down to a safe landing. In a helicopter,
on the other hand, it is vitally imporant that the engine
keeps running and that there is a quick and reliable
response to the throttle in order to ensure safe ascent
and descent of the model.
A
B
The Medium Speed Needle Valve
This is an extra control that can be brought into play,
if necessary, after adjusting A and B above. It
provides the means of fine-tuning mixture strength
over that all-important part of a helicopter's throttle
range where the model is flying in, or near, the
hovering mode.
C
BASIC POSITION OF MIXTURE CONTROL SCREW
(Mixture Control Valve)
Rich
Mixture Control Valve
MIxture Control Screw
Lean
As delivered, the Mixture Control Screw is positioned at
approximately the center as shown in the sketch.
Mixture gets lean when the Mixture Control Screw is
turned right, while mixture gets rich when the Mixture
Control Screw is turned left.With a model helicopter,
adjustments vary with combined various factors such as
climatic conditions, fuel, muffler, main rotor, weight of
the model, gear ratio, etc. Therefore the Mixture Control
Screw position varies with each model and set- up, and
it is normal if the Mixture Control Screw position is off
the center.
89 degrees
When the triangle mark on the carburetor rotor meets
the far right mark, the throttle is fully closed.
When the triangle mark meets the top mark, the throttle
is fully open. The range is 89 degrees. You may use the
other three marks as the reference marking of throttle
opening to your preference when hovering.
WARNING!
Never try to check the triangle mark position while
the engine is running and rotor is rotating, or you
may be hit by rotating rotor which results in serious
injury. Stop the engine and rotor before checking
the triangle mark position.
Carburetor Rotor
Carburetor Body
Fully closed
position
Fully opened position
As shown in the sketch, the carburetor has graduation
marks.
GRADUATIONS ON THE CARBURETOR BODY
Battery leads
1.5 volt dry cell
These are used to conduct current from
the battery to the glowplug. Basically, two
leads, with clips, are required, but, for
greater conve-nience, twin leads with
special glowplug connectors, as shown on
the right, are commercially available.
Battery leads
glowplug Igniter
The power source for heating the glowplug may be
either a large heavy-duty 1.5volt dry cell, Ni-cd battery
or glowplug Igniter.
Glowplug battery
Make sure glowplug element glows
bright red inside room or shadow.
Battery leads
In case of 1.5volt dry cell
12V Battery
Starter
Electric starter and starter battery
An electric starter is recommended
for starting.
Hexagon starting shaft
This shaft mounted on an electric starting motor
is driven into the shaft cup to turn the engine.
Alternatively, one of the purpose-made
manual or electric fuel pumps may be
used to transfer fuel directly from your fuel
container to the fuel tank.
Manual
Electric
It is recommended to install a good
in-line filter between the fuel tank and
carburetor to prevent entry of foreign
matter into the carburetor.
Fuel Filter
Fuel Pump
TOOLS
Screwdriver
Necessary for engine installation.
1.5mm, 2mm, 2.5mm, 3mm
Necessary for carburetor adjustments.
No.1, No.2, etc
Phillips Screwdriver
No.1, No.2, etc.
Socket Drivers
5mm, 5.5mm, 7mm
Hex Drivers
Install a filter to the outlet tube of your
refueling container to prevent entry of
foreign matter into fuel tank. O.S. ‘Super
Filters’ (large and small) are available as
optional extras.
O.S. Super Filter (Fuel Can Filter)
O.S. SPEED PLUG WRENCH
(optional extra)
Loosen the retainer screw, rotate the carburetor to its
correct position and press it well down into the intake
boss, compressing the rubber gasket as shown in the
sketch, before re-tightening screw.
Rotate the retainer screw gently until it stops, then
tighten a further 90-120 degrees. Do not over-tighten
the screw as this will damage the carburetor body.
1.
2.
The High-Speed (Main) Needle Valve
When set to produce maximum power at full
throttle, this establishes the basic fuel/air mixture
strength. This is then maintained by the carburetor's
automatic mixture control system to cover the
engine's requirements at reduced throttle settings.
The Idle Mixture Control Screw
This provides the means of manually adjusting the
mixture control valve. By setting the Mixture Control
Screw for the best idling performance, the mixture
control valve automatically ensures that fuel is
accurately metered to maintain the correct mixture
strength as the throttle is opened.
Three adjustable mixture controls are incorporated in the
Type 40L. They are as follows.
Idle MIxture Control Screw
High Speed Needle Valve
(Main Needle)
Medium Speed
Needle Valve
As the idle mixture control screw is installed
with LOCTITE, it may initialy feel stiff, and it is
suggested to use a slightly oversized
screwdriver. The screw can be turned only 90
degrees either way. Do not force to turn
further, or it may break or cause trouble.
NOTE
90 degrees
90 degrees
Be sure to use an electric starter to start the engine.
Fill the fuel tank with fuel. When filled, prevent the
fuel from flowing into the carburetor with a
commercially available fuel stopper, etc.
Release the stopper before starting the engine.
1.
2.
Starting procedure is as follows:
Make sure that plug element glows red, and install
the plug in the cylinder head.
STARTING
Open
1.
2.
Opening and closing of the Needle-Valve
Turn the needle clockwise to close the needle-valve,
and turn the needle counter-clockwise to open the
needle-valve as shown in the sketch.
High Speed needle-valve:
Idle Mixture Control Screw:
at basic position when the engine leaves the factory.
Medium Speed needle-valve:
Close
4. Checking the rotating direction of the starter
3. Preparation of the starter
Be sure to use a muffler pressurized fuel feed.
Use the same fuel as you intend to employ for
actual operation of your model.
exactly two turns open from the fully closed
position. (Note: If a different muffler is used, this
setting may require readjustment)
exactly two turns open from the fully closed position.
Make sure that the starter rotates
to the direction shown in the
sketch. If the direction is reverse,
reverse the leads on battery.
Install the starting shaft to the
starter securely.
Improper installation will allow the
shaft to swing creating a dangerous
situation.
The connection between the fuel tank and the engine.
ID. 2.5mm Length 1000mm
O.S. SPEED SILICONE FUEL LINE (optional extra)

RUNNING-IN ("Breaking-in")
ADJUSTMENT
CARE AND MAINTENANCE
Please pay attention to the matters described
below to ensure that your engine serves you well
in regard to performance, reliability and long life.
As previously mentioned, it is vitally important to
avoid operating the engine in conditions where dust,
disturbed 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
Filters (L) and (S) are available as optional extras.
Install an in-line fuel filter between the tank and
carburetor to prevent foreign matter in the tank from
entering the carburetor.
If these precautions are neglected, restriction of fuel
flow may cause the engine to cut out, or the fuel/air
mixture to become too lean causing the engine to
overheat.
Clean these filters periodically.
The use of modern high-performance alcohol based
model engine fuels, while promoting cooler running,
improved anti-detonation combustion and increased
power, have the disadvantage of causing corrosion
due to the acid by-products of combustion.
The use of nitromethane in the fuel can also
contribute to the problem.
Do not close the needle-valve and mixture control
valve too far as this will cause a lean setting and
over heating of the engine. This can, in turn, create
nitromethane oxide leading to internal rusting of the
engine. Always adjust the needlevalve slightly on the
rich side of peak rpm.
Do not leave unused fuel in the engine at the
conclusion of a day’s flying. Accepted practice is to
cut off the fuel supply while the engine is still running
at full throttle, then expel as much fuel residue as
possible by turning the engine over 5-10 seconds
with the electric starter.
Finally, inject some after-run oil through the glowplug
hole and turn the engine over several times by hand.
Stopping the engine
Fully pull down the throttle trim on the transmitter.
Starting
Preparation of starting
7.
8.
9.
In case the engine does not stop.
Hold the rotor head, and pinch the fuel line to stop the
fuel supply. If it still does not stop, pull off the fuel line
from the carburetor. It is necessary to readjust the
throttle linkage so that the carburetor rotor is fully
closed when the throttle stick and throttle trim on the
transmitter are fully pulled Down.
NOTE:
If the throttle response is poor or the engine stops
due to a temporarily over-rich mixture immediately
after the engine is started, pinch the fuel line for
one or two seconds until the engine r.p.m.
increase and the engine runs steadily.
Please observe the following before beginning to
make any adjustment.
Medium-Speed Needle Valve.
Turn approximately 30 degrees (3 to 4 clicks) at a time.
ADJUSTMENT PROCEDURE
This condition may also be initiated by an excessively
prolonged warming-up period. lf, on the other hand,
the mixture is too Iean, this wiIl be indicated by a
marked lack of exhaust smoke and a tendency for the
engine to cut out when the throttle is opened. ln this
case, turn the Mixture Control Screw counter-clockwise
5 degrees to enrich the mixture.
Throttle Opening
Fully Closed 1/3 2/3 Fully Open
Fuel Flow
Maximum Minimum
Adjustment range of Idle Mixture
Control Screw
Adjustment range of Medium
Speed Needle Valve
Needle Valve too
far open
Needle Valve too
far closed
High Speed Needle
Valve Setting varies
according to the curve.
SUBSEQUENT READJUSTMENTS
CARBURETOR CLEANLINESS
Remove this with
an 8mm wrench
Dirt and foreign matter
mostly accumulate here
6. Priming
5. Inserting the starter shaft
Insert the starting shaft into the shaft
cup securely.
Without energizing the glowplug,
open the throttle a little from the idle
position. Turn the engine over using
the starter until the fuel is seen to
reach the carburetor.
Connect the battery to the glowplug and start the
engine by applying the starter. When started, switch
off the starter and withdraw the starting shaft after
making sure the rotation of the starter shaft stops.
Hold the rotor head by hand so that
rotor cannot rotate when the engine
is Started. Also, steady the model
with a foot on the landing gear skid.
Make sure that the transmitter
throttle stick is at the fully closed
positionandthethrottletrimatcenter
position, and make sure that idle-up
switch on the transmitter is off.
All internal-combustion engines benefit, to some
degree, from extra care when they are run for the first
few times known as running-in or breaking-in.
This allows the working parts to mate together under
load at operating temperature.
However, because O.S. engines are made with the aid
of the finest modern precision machinely and from the
best and most suitable materrials, only a very short
and simple running-in procedure is required and can
be carried out with the engine installed in the model.
For the first few flights with a new engine i.e. while the
engine is being run-in set the needle-valve for a
slightly rich mixture not excessively rich as this may
result in poor throttle response and cause the engine
to stop.
About one half turn open from the nomal setting will
usually suffice.
High-Speed Needle Valve.
Turn this approximately 30 degrees (3 to 4 clicks) at
a time, when making initial adjustments; then in
steps of approximately 15 degrees (1 to 2 clicks)
when making final adjustments.
Idle Mixture Control Screw.
Turn approximately 5 degrees at a time. It turns
approximately 90 degrees both sides from the
center. Turn left to enrich the idle mixture and turn
right to lean the idle mixture.
The general course of adjustment procedure is
shown in the ADJUSTING CHART and is correct
for a fuel containing 20% lubricant and 15-30%
nitromethane.
Bear in mind that fuels containing relatively large
percentages of power-boosting nitromethane operate
at richer mixture settings than are needed for mild
fuels and will, therefore, require the High-Speed
Needle Valve to be readjusted accordingly. The type
and percentage of lubricant used is also a factor here,
as noted later in these instructions.
This carburetor is not equipped with a throttle stop
screw. Instead, idle speed is adjusted by means of
the throttle trim lever on the transmitter.
As a safety measure, first check the transmitter
controls, including the throttle stick and trim lever
positions, and hold the main rotor securely before
starting the engine.
Warm the engine by allowing it to idle for about 30
seconds. If the engine stops, advance the throttle
trim lever slightly to increase the idle rpm.
Then open the throttle sufficiently to 'float' the model
above the ground. lf, at this time, the engine is slow
to pick up and produces an excess of exhaust
smoke, the mixture is too rich.
Correct this condition by turning the Mixture Control
Screw clockwise 5 degrees. lf the mixture is extremely
rich, engine rpm will become unstable: opening the
throttle will produce a great deal of smoke and rpm
may drop suddenly or the engine may stop.
1.
Having provisionally set the idle mixture, the next step
is to adjust the mixture for hovering flight.
Hover the model and actuate the throttle to observe
response over the medium speed range. lf the engine
smokes excessiveIy and throttle response is poor, the
mixture is too rich ; in which case, land the model and
turn the High-Speed Needle Valve clockwise. Do not
close the High-Speed NeedIe Valve more than the
recommended initial adjustment (3 to 4 clicks) at a
time, keeping it a little on the rich side at this stage. DO
NOT touch the Medium Speed Needle Valve.
lf, on the other hand, hovering is not stable and response
to the throttIe is over-sensitive, or if the engine tends to
overheat, this indicates that the mixture is too lean and
should be corrected by turning the High-Speed Needle
Valve counter-clockwise.
2.
When satisfactory hovering flight has been achieved, land
the modeI again and re-check the engine's idle qualities.
After about 10 seconds of idling, open the throttle to
'float' the model. lf the transition is smooth, the idle
mixture is O.K. If the symptoms of either rich or Iean
running are observed, readjust the Idle Mixture Control
Screw accordingly.
NOTE: With this carburetor, neither the Idle Mixture
Control Screw adjustment, nor the Medium Speed
Needle Valve adjustment will have any effect on
mixture strength when the throttle is fully (or
almost fully) open.
Now adjust the High-Speed Needle Valve to achieve
the best performance when the model is flying at full
throttle. lf, at full throttle, acceleration is poor, the exhaust
unduly smoky and the model fails to reach expected
straight line speed, the mixture is too rich and the
High-Speed Needle Valve setting will need to be
reduced.
lf, however, after smoothly acceIerating to satisfactory
high-speed straight and level flight, power is lost
when the model is puIled up into a climb, the mixture
is too lean. ln this case, land the model immediately
and readjust the High-Speed Needle Valve to a richer
setting.
3.
4. Having now found the optimum setting for the High-Speed
Needle Valve, re-check the engine's idle performance,
fine tuning the Idle Mixture Control Screw, if necessary, to
perfect the idle.
Now re-check hovering performance It may be found
that (with the High-Speed Needle Valve now set for
optimum full-throttle performance) hovering will
reveal symptoms of slightly lean running at medium
speeds. DO NOT touch the High-Speed Needle Valve.
5.
It is at this point that the Medium Speed Needle
Valve, previously set two turns open, may be
brought into operation. Open the Medium Speed
Needle Valve 30 degrees, or 3-4 clicks, then fine
tune until the optimum hovering performance is
obtained.
If on the other hand, hovering reveals rich running,
close the Medium Speed Needle Valve gradually
until the optimum hovering performance is obtained.
Once the engine has been run-in and the carburetor
controls properly set up, it should be unnecessary to alter
the mixture settings, except to make minor changes to the
Main (High-Speed) Needle Valve occasionally, to take
account of differences in climatic condisitions. However,
as previously mentioned, the use of a different fuel,
particularly one containing more, or less, nitromethane
and / or a different type or proportion of lubricating oil, is
likely to call for some modification to the High-Speed
Needle-Valve adjustment. As a safety measure, it is
advisable to increase the High-Speed Needle Valve
setting by an extra half-turn counter-clockwise, prior to
establishing the new setting. The same applies if the
silencer type is changed. A different silencer may alter the
exhaust pressure applied to the fuel feed and call for a
revised Needle-Valve setting. The use of a different
glowplug, or changes to the main rotor and its pitch
angles may also require compensating carburetor
readjustments.
The correct functioning of the carburetor depends on
its small fuel orifices remaining clear. The minute
particles of foreign matter that are present in any fuel
can easily partially obstruct these orifices and upset
mixture strength so that engine performance becomes
erratic and unreliable. It is recommended that fuel is
passed through a filter when the tank is filled and that
a good in-line filter is installed between the fuel tank
and carburetor and, furthermore, that this filter is
frequently cleaned to remove foreign matter that
accumulates on the filter screen. Finally, occasionally
remove the needle-valve holder from the carburetor as
shown in Photo and extract any remaining foreign
matter that may have lodged in the location shown in
Photo, below.

Dimensions (mm)
THREE VIEW DRAWING
ENGINE EXPLODED VIEW & PARTS LIST
Type of screw
C…Cap Screw
The specifications are subject to alteration for improvement without notice.
CARBURETOR EXPLODED VIEW & PARTS LIST
(55500002)
(71605100)
(71608001)
(71607100)
C121402
Copyright 2013 by O.S. Engine Mfg. Co., Ltd. All rights reserved. Printed in CHINA.
http://www.os-engines.co.jp
6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan
TEL. [phone]
FAX. [phone]
O.S. GENUINE PARTS & ACCESSORIES
(72403050)
(71531000)
(L)
NON-BUBBLE WEIGHT
SUPER FILTER
M3
LOCK WASHER (10set)
GLOWPLUG
No.10 (Former A5)
No.8
No.7
When the engine is not to be used for some months
(for example, as between flying seasons), a worthwhile
precaution is to remove it from the airframe and, after
washing off the exterior with alcohol (not gasoline nor
kerosene), remove carefully the carburetor with intake
pipe, glow plug and all silicone tubing and put them
safely aside. Then, immerse the engine in a container
of alcohol. Rotate the crankshaft while the engine is
immersed. If foreign matter is visible in the alcohol,
rinse the engine again in clean alcohol. Finally, shake
off and dry the alcohol, and inject some after-run oil in
the glowplug hole and rotate the crankshaft several
times by hand. Reinstall the carburetor with intake pipe
and glowplug on the engine and keep it in a dry place
after putting in a vinyl bag.
POWERBOOST PIPE 55
POWERBOOST PIPE 55
3246
CRANKSHAFT CLAMP
(71531010)
(S)
NON-BUBBLE WEIGHT
(71520100)
O.S. SPEED PLUG WRENCH
The specifications are subject to alteration for improvement without notice.
Type of screw
C…Cap Screw
The specifications are subject to alteration for improvement without notice.
(71530400)
(72144000)
(72147000)
3
4-1
4-2
4-3
4
5
6
7
8
9-1
9-2
9-3
9-4
9
11-1
11-2
11-3
11-4
10
3-1
12
C.M2.6x7
2
C.M3x8
1
1-1
11
8.93 cc / 0.55 cu.in.
23 mm / 0.91 in.
21.5 mm / 0.85 in.
2.1 ps / 2.07 hp / 17,000 r.p.m.
2,000-20,000 r.p.m.
408g / 14.40 oz.
79871055 M2.6x18
CAP SCREW SETS (10pcs./sets)
Code No. Size Pcs. used in an engine
Retainer Screw (1pc.)
1
1-1
2
3
4
5
6
7
8
9
10
11
12
12-1
13
14
15
16
17
18
25804000
25804160
25803100
27703400
25803200
25806000
25217000
25205000
25881000
23210007
46120000
26731002
25881700
45566310
25801000
25830000
25802000
25804170
25807001
25613000
71608001
Heatsink Head
Head Gasket (0.2mm)
Cylinder Liner
Piston Ring
Piston
Piston Pin
Piston Pin Retainer (2pcs.)
Connecting Rod
Carburetor Complete 40L
Propeller Nut
Thrust Washer
Crankshaft Ball Bearing (Front)
Carburetor Retainer Assembly
"O" Ring
Crankcase
Crankshaft Ball Bearing (Rear)
Crankshaft
Cover Gasket
Cover Plate
Screw Set
Glow Plug No.8
No. Description
Code No.
Throttle Lever Assembly
Throttle Lever Retaining Screw (2pcs.)
Carburetor Rotor
Rotor Guide Washer
Rotor Guide Washer Retaining Screw
Mixture Control Valve Assembly
"O"Ring (L) (2pcs.)
"O"Ring (S) (2pcs.)
"O"Ring (2pcs.)
Rotor Guide Screw
Carburetor Body
Mixture Control Screw
Mixture Control Valve Stopper
Needle Valve Assembly (Main Needle)
Needle Assembly
"O"Ring (2pcs.)
Needle Valve Holder Assembly
Ratchet Spring
Fuel Inlet
Needle Valve Assembly
Needle Assembly
"O"Ring (2pcs.)
Needle Valve Holder Assembly
Ratchet Spring
Carburetor Rubber Gasket
(72506100) 2.5mm x 1000mm
O.S. SPEED SILICONE FUEL LINE
C.M3x15
1
2
3
4
5
6
7
8
910
11
12
14
15
18
13 12-1
C.M2.6x18
C.M3x8
16
17
1-1
37.7
11.5
37
31 51.6
44
17.5
UNF1/4-28
18.3
51.6 25
72.6
54
52
36
38
47
1
1-1
2
3
3-1
4
4-1
4-2
4-3
5
6
7
8
9
9-1
9-2
9-3
9-4
10
11
11-1
11-2
11-3
11-4
12
29085140
22826131
25881200
25881220
79871020
29085510
27881810
27881800
27881820
45581820
25881100
27881330
27681340
29085900
29085910
24981837
29085940
26711305
29085950
27981900
27981910
24981837
27381940
26711305
29015019
No. Description
Code No.
Displacement
Bore
Stroke
Output
Practical R.P.M.
Weight (Engine)
SPECIFICATIONS