O.S. Engines 32SX-HX User Manual

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Page 1

It is of vital importance, before attempting to operate your engine, to read the general

'SAFETY INSTRUCTIONS AND WARNINGS'

section on pages 2-5 of this booklet 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.

Keep these instructions in a safe place so that

•

you may readily refer to them whenever necessary.

It is suggested that any instructions supplied

•

with the model, radio control equipment, etc., are accessible for checking at the same time.

Page 2

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

CONTENTS

2~5

SUBSEQUENT READJUSTMENTS

INTRODUCTION

BASIC ENGINE PARTS, INSTALLATION

NOTES CONCERNING THE RECOIL STARTER

BEFORE STARTING

FACTS ABOUT GLOW PLUGS FUEL

CARBURETOR CONTROLS

STARTING

RUNNING-IN,ADJUSTMENT

8~10

18 19

20 21

CARBURETOR CLEANLINESS

ADJUSTING CHART

INSTALLATION OF THROTTLE SERVO

CARE AND MAINTENANCE

ENGINE EXPLODED VIEW & PARTS LIST

CARBURETOR EXPLODED VIEW & PARTS LIST

THREE VIEW DRAWING

O.S. GENUINE PARTS & ACCESSORIES

Page 3

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

Remember that your engine is not a "toy", but a highly efficient internalcombustion 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.

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.

Page 4

•

Never touch, or allow any object to come into contact with, the rotating parts.

Model engine fuel is poison-

•

ous. 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.

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.

WARNINGS

•

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

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.

Page 5

NOTES

These engine were designed for model

•

helicopters. Do not attempt to use it for any other purpose.

Mount the engine in your model securely, fol-

•

lowing the manufacturers' recommendations, using appropriate screws and locknuts.

Install an effective silencer (muffler). Frequent

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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

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each flight. Avoid sudden high r.p.m. immediately after the

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engine is started, as the clutch will engage and you may be struck by the rotor.

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 carburettor.

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.

Page 6

Take care that loose clothing (ties, shirt sleeves,

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scarves etc.) do not come into contact with the rotor. Do not carry loose objects (such as pencils, screwdrivers, etc.) in a shirt pocket from where they could fall through the rotor disc.

For their safety, keep all onlookers (especially

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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

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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.

NOTES

Do not attempt to disassemble the recoil

•

starter (if fitted). If you do so, the very strong spring inside will be suddenly ejected. This can be very dangerous.

Do not extend the starter cord more than 45cm

•

(18"). Do not abruptly release the operating handle. Allow the cord to rewind smoothly while still holding the handle.

Pull the operating handle straight out when

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stating the engine, so that the cord does not rub against the helicopter structure or engine. This will help prevent the cord from being damaged by abrasion or engine heat.

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INTRODUCTION

These engines are produced by the world's oldest and largest model engine manufacturing company ; a company that has designed and manufactured all types of engines, large and small : two-stroke, fourstroke, Wankel-rotary, supercharged, twin nand multi-cylinder four-strokes and has also produced more helicopter units than any other maker worldwide. Highperformance motors, designed for small-sized radio-controlled helicopters, the MAX-32SX-H Series is available in a choice of three versions. The standard 32SX-H features ABC cylinder/piston construction, whereas the 32SX-H Ring employs a compression-ring equipped piston, while the 32SX-HX Ring has the addition of an O.S. Recoil Starting System to eliminate the need for a separate electric starter and battery.

The close-fitting ringless piston of the standard 32SX-H will feel tight at the top of its stroke when the engine is cold. This is normal. The piston and cylinder are designed to achieve a perfect running clearance when they reach their normal running temperature.

Note: 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 hightorque type starter. DO NOT,however, confuse tightness with the symptoms of hydraulic lock caused by an excess of fuel within the cylinder

- often the result of over-priming. Attempting to force the engine to turn over in this condition may cause internal damage. Instead, remove the glowplug,invert the engine and eject surplus fuel from the combustion-chamber.

Page 8

BASIC ENGINE PARTS

Glowplug

Carburetor Typr 20C

Beam Mount

Needle valve

Propeller nut

Crankshaft

Heatsink Head

Crankcase

Recoil Starter Assembly No.O

Starter Handle

MAX-32SX-HX

INSTALLING THE GLOWPLUG

Install washer on glowplug and insert carefully into cylinder-head, making sure that it is not cross-threaded before tightening firmly.

Glow plug

Washer

INSTALLATION

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.

Page 9

CORRECT

Front view

Top surfaces are in the same plane.

Side view

INCORRECT

Note:

As the recoil starter is of unit construction, re-

1. placement parts are not available. Replacement recoil starters are obtainable only as complete units.

Do not pull the starter cord more than 50cm (20

2. in.). Do not abruptly release the starter knob. Allow the cord to rewind slowly by holding on to the knob.

Pull the knob straight so that the cord does not

3. touch the helicopter body, etc.

Top surfaces are not in the same plane.

Re-align the surfaces as necessary

Top surfaces are not in the same plane.

Engine does not rest firmly.

BEFORE STARTING

Tools, accessories, etc.

The following items are necessary for operating the engine.

1 Fuel

NOTES CONCERNING THE RECOIL STARTER

( 32SX-HX ONLY)

Warning! Do not attempt to disassemble the recoil starter: the very strong spring inside will spring out,

Model glowplug engine fuel of good quality, preferably containing a small percentage of nitromethane.

2 Glowplug

O.S. A3 glowplug is installed in the engine.

which is very dangerous.

Page 10

3 Glowplug battery

The power source for heating the glowplug may be either a large heavy-duty 1.5volt dry cell, or preferably, a 2-volt rechargeable lead-acid cell.

If a 2-volt cell is employed, use a resistance wire, as shown, to reduce applied voltage, otherwise element

1.5 volt heavy-duty dry battery

or 2 volt rechargeable lead-acid cell (at least 5Ah)

will overheat and burn out.

Warning (Very hot)

Never touch the nichrome wire while the battery is connected.

Resistance coil (nichrome wire)

Battery leads

Adjust applied voltage by changing the position of clip on resistance coil until glowplug element is glowing bright red.

Raise

voltage to

increase

brightness.

Lower voltage to

reduce brightness.

4 Plug wrench

Used for tightening glowplug. The O.S. long plug wrench is available as an optional accessory.

5 Battery leads

These are used to conduct current from the battery to the glowplug. Basically, two leads, with clips, are required, but, for greater convenience, twin leads with special glowplug connectors, as shown on the right, are commercially available.

6 Fuel bottle or pump

For filling the fuel tank, a simple, polyethylene "squeeze" bottle, with a suitable spout,is all that is required. 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.

For tightening glowplug

Battery leads

Fuel bulb

Fuel pumps

Manual

Electric

Page 11

7 Fuel container filter

Install a filter on the outlet tube of your refuelling container to prevent entry of foreign matter into the fuel tank

8 Silicone tubing

This is required for the connection between the fuel tank and engine.

9 Hexagon starting shaft

This shaft mounted on an electric starting motor is driven into the main body of a helicopter to turn the engine.

10 Electric starter and starter battery

An electric starter is recommended for starting.

Fuel Can Filter

Silicone tube

12V Battery

Starter

FACTS ABOUT GLOWPLUGS

Since the compatibility of glowplug and fuel may have a marked effect on performance and reliability, it may be worthwhile to choose the R/C type plug found most suitable after tests.Recommended O.S. plugs are No.8, A5 and A3. Carefully install plug finger-tight, before final tightening with the correct size plug wrench.

The role of the glowplug

With a glowplug engine, ignition is initiated by the application of a 1.5-volt power source. When the battery is disconnected, the heat retained within the combustion chamber remains sufficient to keep the plug filament glowing, thereby continuing to keep the engine running. Ignition timing is 'automatic' : under reduced load, allowing higher rpm, the plug becomes hotter and, appropriately, fires the fuel/air charge earlier; conversely, at reduced rpm, the plug become cooler and ignition is retarded.

Glowplug life

Particularly in the case of very high performance engines,

glowplugs must be regarded as expendable

Page 12

However, plug life can be extended and engine performance maintained by careful use, i.e.:

Install a plug suitable for the engine.

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Use fuel containing a moderate percentage of

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nitromethane. Do not run the engine too lean and do not leave the

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battery connected while adjusting the needle.

When to replace the glowplug

Apart from when actually burned out, a plug may need to be replaced because it no longer delivers its best performance, such as when:

Filament surface has roughened and turned white.

•

Filament coil has become distorted.

•

Foreign matter has adhered to filament or plug

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body has corroded. Engine tends to cut out when idling.

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Starting qualities deteriorate.

•

FUEL

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. Select by practical tests when using such fuels.

Reminder!

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.

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.

Page 13

CARBURETOR CONTROLS

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.

Two adjustable controls are provided on this carburetor.

The Needle Valve:

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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 Mixture Control Valve (Mixture ControlScrew):

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For adjusting the mixture strength at part-throttle and idling speeds, to obtain steady idling and smooth acceleration to medium speeds. The Mixture Control Valve has been factory set for the approximate best result. First, run the engine as received, and re-adjust the Mixture Control Valve only when necessary.

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. Its basic setting can be reestablished as follows : The basic ( factory ) setting is as shown in the main sketch, i. e. with the shoulder portion 'A' exactly at a tangent to the throttle rotor hole.To return the Mixture Control Valve to its original position, first screw in the Mixture Control Valve, while looking into the rotor hole. Then gradually unscrew the Mixture Control Valve until 'A' is precisely tangential to the rotor hole (i.e. so that 'A' and 'B' are superimposed) as in the main sketch.

Needle Valve

Mixture Control Valve (MIxture Control Screw)

Rotor Guide Screw

Throttle Lever

Mixture Control Valve (MIxture Control Screw)

Nozzle

Throttle Rotor Hole

Page 14

STARTING (32SX-H / SX-H RING)

Be sure to use a muffler pressu-

1. rized fuel feed. Use the same fuel as you intend to employ for actual operation of your model. Open the needle-valve 1- 1/2 turns.

Open the throttle fully, and turn

the engine using an electric starter until the fuel is seen to reach the carburetor. Fuel may be drawn to the carburetor more quickly by choking the exhaust outlet with a finger, while operating the starter.

Do not continue to choke the exhaust after fuel has

reached the carburetor.

Now reset the transmitter throttle stick to the closed

4. position, keeping the throttle trim lever set at the advanced (i.e. idle)

Hold the rotor head by hand so that the rotor cannot rotate when the engine is started. Also, steady the model with a foot on the landing-gear skid.

Connect the battery to the glowplug and start the engine by applying an electric starter.

position.

Needle-Valve

Open

STARTING (32SX-HX RING)

Be sure to use a muffler pressurized fuel feed. Use

1. the same fuel as you intend to employ for actual operation of your model. Open the needle-valve 11/2 turns.

Open the throttle fully, and pull the recoil starter

2. knob until the fuel is seen to reach the carburetor. Fuel may be drawn to the carburetor more quickly by choking the exhaust outlet with a finger, while operating the starter.

After fuel reaches the carburetor, pull the starter

3. knob two or three times so that fuel may be drawn well into the engine.

NOTE: Do not choke the exhaust at this time.

Now reset that the transmitter throttle stick to the

closed position, keeping the throttle trim lever in the advanced (i.e. idle)

Hold the rotor head by hand so that the rotor cannot rotate when the engine is started. Also, steady the model with a foot on the landing-gear skid.

position.

Page 15

Connect the battery to the glowplug and pull the start knob smartly.

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.

Reminder!

Never touch, or allow any object to come into contact with, the rotating rotor.

RUNNING-IN ("Breaking-in")

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

short and simple running-in procedure is required and can be carried out with the engine installed in the modle. 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 stope. About one-half turn open from the nomal setting will usually suffice.

ADJUSTMENT

The following adjustments are approximately correct when using a fuel containing 25% lubricant and 1030% 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 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 fitted with a throttle stop screw.Instead, idling speed is adjusted by means of the throttle trim lever on the transmitter.

Page 16

This enables the full r.p.m. range, from idling to full power, to be controlled by the throttle stick, and then allows the engine to be stopped, from the transmitter, by closing the throttle completely with the trim lever. Set up the throttle linkage as follows: With the transmitter throttle trim lever fully retarded, adjust the throttle servo linkage so that the throttle rotor is (a) fully open when the transmitter throttle stick is fully advanced and (b)

closed (i.e. engine stopped) when the stick is

fully

retarded.The idling speed is then set by

fully advancing the throttle trim lever to the point where the engine runs, steadily and reliably,at the desired idling speed.

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.(Refer to page 13.)

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 idling 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. 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. 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 to enrich the mixture.

Turn the Mixture Control Screw 30 degrees at a

time. Having provisionally set the idle mixture, the next

step is to adjust the mixture for hovering flight.

Page 17

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 Needle Valve clockwise. Do not close the NeedIe Valve too much, keeping it a little on the rich side at this stage.

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 Needle Valve counter-clockwise.

When satisfactory hovering flight has been achieved, land the modeI again and re-check the engine's idlling 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 Control Screw accordingly.

Now adjust the Needle Valve to achieve the best

performance when the model is flying at full throttle. lf, at full throttle, acceleration is poor, the

observed, readjust the Mixture

exhaust unduly smoky and the model fails to reach expected straight line speed, the mixture is too rich and the 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 Needle Valve to a richer setting.

Now re-check hovering performance and, if necessary, fine-tune the mixture for hovering flight.

For helicopters, good throttle response at medium r.p.m. (e.g.hovering speeds) is most important, since this is a power range widely used in helicopter flight. The optimum fuel/air mixture strength at medium speeds is dependent on obtaining balanced adjustment of both the Needle Valve and the Mixture Controlof both the Needle Valve and the Mixture Control Valve. lf both controls are already at their optimum setting, some modification to these settings may be necessary to achieve satisfactory mid-range throttle response, but such readjustments should onIy be made within the range where idling reliability and highspeed performance are not unduly compromised.

Page 18

Readjustments should therefore be carried out as follows:

lf the mid-range throttle response is not rapid and

positive (indicating a rich mid-range mixture), turn the Needle Valve 2 or 3 clicks clockwise, or turn the Mixture Control Screw 10-20 degrees cIockwise.

lf, on the other hand, the response to mid-range

throttle movement is too sensitive (indicating a lean mid-range mixture), turn the Needle Valve 2 or 3 clicks counter-clockwise or turn the Mixture Control Screw 10-20 degrees counter-clockwise.

Throttle response at hovering speeds is aIso affected by the reIationship of the main rotor pitch angle to throttle opening. If the optimum mid-range throttle response cannot be obtained by the carburettor adjustments described above, try adjusting the helicopter's pitch control characteristics.

SUBSEQUENT READJUSTMENTS

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 adjustments to the Needle Valve occasionally, to take account of variations in climatic condisitions. The use of a different fuel, however, particularly one containing more, or less, nitromethane and / or a different type or proportion of lubricating oil, is likely to call for some readjustment of the Needle-Valve. Remember that, as a safety measure, it is advisable to increase the Needle Valve opening by an extra half-turn counter-clockwise, prior to establishing a 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 mainrotor and its pitch angles may also require compensating carburettor readjustments.

Page 19

CARBURETOR CLEANLINESS

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 carburettor and, furthermore, that this filter is frequently cleaned to remove dirt and lint 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, right.

Remove this with an 8mm spanner

Dirt and fbrous matter mostly accumulate here

Page 20

ADJUSTING CHART

Open the Needle Valve 1-1/2 turns from the fully closed position. Make sure that the Mixture Control Valve is at the factory setting.

Observe the mixture condition while "floating" the model

Turn the Mixture Control Screw counter-clockwise

Open the Needle Valve (Turn counter-clockwise)

Turn the Mixture Control Screw counter-clockwise

Open the Needle Valve (Turn counter-clockwise)

P Turn the Needle Valve

2 or 3 clicks counterclockwise, or turn the Mixture Control Screw 2-3 degrees counterclockwise. Adjust pitch control characteristics.

Lean mixture

Idle for approx: 10 seconds, then reopen throttle to observe transition ("Float" the model)

Lean mixture

Response too sensitive

Start the engine

Warm up the engine

Rich mixture

Observe the hovering mixture condition

Fine tuning of hovering mixture

Idling OK

Hovering OK

Land the model

Idling OK

High Speed Flight

High Speed Flight OK

Hovering OK

Adjustment completed

Rich mixture

Response too slow

Turn the Mixture Control Screw clockwise

H Close the Needle Valve (Turn clockwise)

Turn the Mixture Control Screw clockwise

Close the Needle Valve (Turn clockwise)

Turn the Needle Valve 2 or 3 clicks clockwise, or turn the Mixture Control Screw 2-3 degrees clockwise. Adjust pitch control characteristics.

Page 21

INSTALLATION OF THROTTLE SERVO

After the engine in the helicopter, please observe the following recommendations when linking the throttle servo to the carburettor.

When the throttle is fully open or fully closed, the throttle lever angle should not be more than 45˚ either side of the mid-point of its travel (and where it is at a 90˚ angle to hte pushrod), otherwise throttle rotor movement may become inhibited or may even lock up. Also, some lubricants may affect the throttle rotor movement. Please note that the throttle lever angles of the O.S. Type 20C carburettor are well within these limits-requiring only 75˚ from the fully open to fully closed positions.

INCORRECT-One-way throttle lever movement should not be more than 45

Fully closed position

90˚

Locate the servo so that its output arm and the throttle pushrod are, as closely as possible, directry in line with carburetor's throttle arm, as shown.

CORRECT-Throttle lever movement should be disposed symmetrically,as shown.

90˚

Fully open position

Note : If differential throttle movement is required, make necessary adjustment at the servo output arm, not at the throttle lever.

Use outer hole.

Page 22

CARE AND MAINTENANCE

The minute particles of foreign matter, that are

present in any fuel may, by accumulating and partially obstructing fuel flow, cause engine performance to become erratic and unreliable. O.S. 'Super-Filters' (large and small)are available, as optional extras, to deal with this problem. One of these filters, Installed on the outlet tube inside your refueling container, will prevent the entry of foreign material into the fuel tank. It is also recommended that a good in-line filter be installed between the tank and carburetor.

Do not forget to clean the filters regularly to remove

dirt and lint that accumulate on the filter screens. Also, clean the carburetor itself occasionally.

At the end of each operating session, drain out any

fuel that may remain in the fuel tank. Next, energize the glowplug and try ot restart the engine to burn off any fuel that may remain inside the engine. Repeat this procedure until the engine fails to fire. Remove the glowplug and eject any remaining fuel/oil residue by rotating the engine with an electric starter for 4 to 5 seconds while the engine is still warm.

Finally, inject some after-run oil into the engine.

Rotate the engine a few times by hand, to make sure that it is free, and then with an electric starter for 4 to 5 seconds to distribute the oil to all the working parts.

Note: Do not inject after-run oil into the carburettor as this may cause the O-rings inside the carburetor to deteriorate.

These procedures will reduce the risk of starting difficulties and of internal corrosion after a period of storage.

Page 23

EXPLODED VIEW (MAX-32SX-H / 32SX-HRING)

C.M2.6X12

-1

-2

✽

Type of screw

…

Cap Screw M…Oval Fillister-Head Screw

…

Flat Head Screw N…Round Head Screw S…Set Screw

N.+M3.5X5

C.M2.6X7

Page 24

ENGINE PARTS LIST (MAX-32SX-H / 32SX-HRING)

No.

Code No.

23404000

23403000

23406000

23405000

23481000

-1

22615000

-2

23081706

23210007

22620003

22831000

23401000

23430000

23402000

23414000

22907000

22413009

23403100

22903400

23403200 71605300

The specifications are subject to alteration for improvement without notice.

Heatsink Head Cylinder & Piston Assembly(For 32SX-H) Piston Pin Connecting Rod Carburetor Complete(Type 20C) Carburetor Rubber Gasket Carburetor Retaining Screw(2pcs.) Propeller Nut Thrust Washer Crankshaft Ball Bearing(Front) Crankcase Crankshaft Ball Bearing(Rear) Crankshaft Gasket Set Cover Plate Screw Set Cylinder Liner(For 32SX-HRING) Piston Ring(For 32SX-HRING) Piston(For 32SX-HRING)

Glowplug A3

Description

Page 25

EXPLODED VIEW (MAX-32SX-HXRING)

C.M2.6X12

-1

-2

✽

Type of screw

…

Cap Screw M…Oval Fillister-Head Screw

…

Flat Head Screw N…Round Head Screw S…Set Screw

F.M2.6X10

N.+M3.5X5

-1

-2

N.+M3X8

Page 26

ENGINE PARTS LIST (MAX- 32SX-HXRING)

Code No.

No.

23404000

23403100

22903400

23403200

23406000

23405000

23481000

-1

22615000

7-2

23081706

23210007

22620003

22831000

23401000

23430000

23402010

23414000

22921210

22921110

27381210

72801000

-1

72801100

y-2

72801102

22913010 71605300 72405000 22781411

The specifications are subject to alteration for improvement without notice.

Heatsink Head Cylinder Liner Piston Ring Piston Piston Pin Connecting Rod Carburetor Complete(20C)

Carburetor Rubber Gasket

Carburetor Retaining Screw(2pcs.) Propeller Nut Thrust Washer Crankshaft Ball Bearing(Front) Crankcase Crankshaft Ball Bearing(Rear) Crankshaft Gasket Set Starting Shaft Rear Housing Starting Shaft Bearing Recoil Starter Assembly No.0

No.0 Recoil Starter Body

No.0 One-way Clutch Screw Set

Glowplug A3

Landing Gear Mounting Plate Throttle Lever

Description

Page 27

CARBURETTOER PARTS LIST & EXPLODED VIEW

-2

-1

✽

Type of screw C…Cap Screw M…Oval Fillister-Head Screw

F…Flat Head Screw N…Round Head Screw S…Set Screw

No.

Code No.

23481400

-1

22781410

-2

22781420

22781411

23481200

23481650

23481100

-1

24881824

26781506 45581820

22681953

27681900

27681970

-1

24981837

-2 26381501

-3 27381940

-4 26711305

-5 22615000

23081706

The specifications are subject to alteration for improvement without notice.

-1

N.+M3.5X5

Throttle Lever Assembly

Throttle Lever

Throttle Lever Retaining Screw Throttle Lever Carburetor Rotor Mixture Control Valve Spring Carburetor Body

"O"

Ring (2pcs.) Rotor Spring Rotor Guide Screw Fuel Inlet Needle Valve Assembly

Needle

"O"

Ring (2pcs.)

Set Screw Needle Valve Holder

Ratchet Spring Carburetor Rubber Gasket Carburetor Retaining Screw

Description

-4

-5

-2

-1

-3

S.M3X3

Page 28

MAX-32SX-H/32SX-HRING THREE VIEW DRAWING

SPECIFICATIONS

Displacement

■

Bore

■

Stroke

■

Practical R.P.M.

■

Power output

■

Weight

■

5.23 cc (0.319 cu.in.

19.5mm (0.768 in.

17.5mm (0.689 in.

22,000 r.p.m.

2,000

1.2 bhp / 18,000 r.p.m. 290g(10.23oz.) SX-H 285g(10.06oz.) SX-H

) ) )

RING

Dimensions(mm)

Page 29

MAX-32SX-HXRING THREE VIEW DRAWING

SPECIFICATIONS

Displacement

■

Bore

■

Stroke

■

Practical R.P.M.

■

Power output

■

Weight

■

5.23 cc (0.319 cu.in.

19.5mm (0.768 in.

17.5mm (0.689 in.

21,000 r.p.m.

2,000

1.15 bhp / 17,000 r.p.m. 387g(13.66oz.)

) ) )

Dimensions(mm)

Page 30

O.S. GENUINE PARTS & ACCESSORIES

DRIVE HUB

■

(23408000)

E-3030 SILENCER

■

(23325020)

BOOSTER TERMINAL KIT

■

FOR 'SHUTTLE'

(72200160)

SUPER FILTER

■

) (72403050)

(

O.S. GLOW PLUGS

■

No.8

(71608001)

CRANKSHAFT CLAMP

■

3261

(71605100)

(For 32F-H, SX-H, 61SX-H,RX-H )

3246 (For 32SX-H, 46FX-H )

(71530300)

(71530400)

843 SILENCER

■

EXTENSION ADAPTOR

(23325100)

LONG SOCKET WRENCH

■

WITH PLUG GRIP

(71521000)

EXHAUST

■

ADAPTORS 90 degree

(22625508)

Page 31

MEMO

Page 32

6-15 3-Chome Imagawa Higashisumiyoshi-ku Osaka 546-0003, Japan

URL : http://www.os-engines.co.jp

TEL. (06) 6702-0225

FAX. (06)6704-2722

100102