O.S. Engines 32SX User Manual

MAX-15CV-A, 25FX, 32SX

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

'SAFETY INSTRUCTIONS AND WARNINGS' section on pages 2-6 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 aircraft, radio control equipment, etc., are accessible for checking at the same time.

CONTENTS

SAFETY INSTRUCTIONS AND	2~6
WARNINGS ABOUT YOUR O.S. ENGINE
INTRODUCTION,	7
BEFORE INSTALLING THE ENGINE
BASIC ENGINE PARTS	8
CARBURETOR PARTS
INSTALLATION OF THE ENGINE	9
THROTTLE LINKAGE, SILENCER	10~11
FUEL TANK LOCATION	11
GLOWPLUG	12
FUEL, PROPELLERS	13~14
MIXTURE CONTROLS	14
BEFORE STARTING	14~16
STARTING	16~17

RUNNING-IN (Breaking-in)	17~19
IDLING ADJUSTMENT CHART	20
MIXTURE CONTROL VALVE ADJUSTMENT,	21
REALIGNMENT OF MIXTURE CONTROL VALVE
SUBSEQUENT STARTING PROCEDURE	22
SUBSEQUENT READJUSTMENT
CARBURETOR CLEANLINESS,	23
ENGINE CARE AND MAINTENANCE
GENUINE O.S. PARTS & ACCESSORIES	24~25
ENGINE EXPLODED VIEWS &	26~29
ENGINE PARTS LISTS
CARBURETOR EXPLODED VIEWS	30~31
& PARTS LISTS
ENGINE THREE VIEW DRAWING	31~32

1

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.

2

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.

•A weakened or loose propeller may disintegrate or be thrown off and, since propeller tip speeds with powerful engines may exceed 600 feet(180 metres) per second, it will be understood that such a failure could result in serious injury, (see 'NOTES' section relating to propeller safety).

•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.

•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.

3

NOTES

•This engine was designed for model aircraft. 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.

•Be sure to use the silencer (muffler) supplied with the engine. 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.

•If you remove the glowplug from the engine and check its condition by connecting the battery leads to it, do not hold the plug with bare fingers.Use an appropriate tool or a folded piece of cloth.

•Install a top-quality propeller of the diameter and pitch specified for the engine and aircraft. Locate 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 nut, using the correct size wrench.

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NOTES

•Always check the tightness of the propeller nut and retighten it, if necessary, before restarting the engine, particularly in the case of four-stroke-cycle engines. If a safety locknut assembly is provided with your engine, always use it. This will prevent the propeller from flying off in the event of a "backfire", even if it loosens.

•If you fit a spinner, make sure that it is a precision made product and that the slots for the propeller blades do not cut into the blade roots and weaken them.

•Preferably, use an electric starter. The wearing of safety glasses is also strongly recommended.

•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, unless you are highly experienced in tuning propellers for specialized competition work such as pylon-racing.

•Take care that the glow plug clip or battery leads do not come into contact with the

propeller. Also check the linkage to the throttle arm. A disconnected linkage could also foul the propeller.

•After starting the engine, carry out any needle-valve readjustments from a safe

position behind the rotating propeller. Stop the engine before attempting to make other adjustments to the carburetor.

5

NOTES

•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 propeller.Do not carry loose objects (such as pencils, screwdrivers, etc.) in a shirt pocket from where they could fall through the propeller arc.

•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.

•For their safety, keep all onlookers (especially small children) well back (at least 20 feet or 6 meters) 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. Keep the propeller pointed away from you and walk well clear of spectators.

•Warning! Immediately after a glowplugignition engine has been run and is still warm, conditions sometimes exist whereby it is just possible for the engine to abruptly restart if the propeller is casually flipped over compression WITHOUT the glowplug battery being reconnected. Remember this if you wish to avoid the risk of a painfully rapped knuckle!

6

INTRODUCTION

•This range of engines is ideally suited to a variety of R/C aircraft, including trainer, sports, aerobatic and scale types.

•A separate precision-made needle-valve unit is installed at the rear, where manual adjustment is safely remote from the rotating propeller.

Note :

With these engines, the piston 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 intended running temperature.

BEFORE INSTALLING THE ENGINE

Installing the glowplug

Carefully insert plug, with washer, fingertight only, before final tightening with the correct

size plug wrench.

Glow plug Washer

Connecting fuel tubing

Connect the short length of fuel tubing (supplied) securely between the needle-valve outlet and carburetor inlet as shown in the illustration on the next page.

In the event of the tubing becoming damaged, it should be replaced with a suitable length (as indicated below) of best quality 5mm ODx2mm ID silicone tubing. Use similar material to connect the fuel inlet nipple to the fuel tank.

Length

15CV-A 44mm

25FX 38mm

32SX 44mm

7

BASIC ENGINE PARTS

Cylinder head	Glowplug
Throttle Stop	Fuel inlet
Screw
Carburetor
	Needle valve

		Fuel outlet
Throttle Lever		Cover Plate
		Silicone Tube
	Fuel inlet	Beam Mount
	Crankcase
	Drive Hub
Crankshaft	Propeller washer
	Propeller nut	MAX-15CV-A

INSTALLATION OF THE CARBURETTOR

For 15CV-A

1.Loosen the retainer screw, rotate the carburettor to its correct position and make sure that it is pressed well down into the intake boss, compressing the rubber gasket, before retightening screw.

2.Rotate the retainer screw gently until it stops, then tighten a further 60-90˚.

Do not overtighten the screw as this will damage the carburettor body.

	Rotate the retainer nut	Tighten a further 60-90˚
	gently until it stops.

8

INSTALLATION OF THE ENGINE

Installation in the model

A typical method of beam mounting is shown below, left.

Rigid hardwood (e.

O.S. radial motor mount (Available as an optional extra part. See parts list)

At		12mm(1/2")
12mm(1/2")
15CV-A		For CZ, 15CV-A(Code No. 71909410)
25FX/32SX		For 25FX¡32SX(Code No. 71908410)
		Retaining Screw Size
		15CV-A	3.0mm
		25FX	3.0mm
		32SX	3.0mm

Make sure that the mounting beams are parallel and that their top surfaces are in the same plane.

	CORRECT		INCORRECT
			Top surfaces	Opposite
	Front view	Side view	are not in the	beam	Top surfaces
			same plane.
	Top surfaces are in				are not in the
					same plane.
	the same plane.		Re-align the surfaces
			as necessary		Engine does not
					rest firmly.

How to fasten the mounting screws.

3mm steel nuts

Tighten second nut firmly down onto first nut.

	Spring	Tighten this nut first.		3mm steel
				Allen screw
	washer or
	lock washer
		Hardwood such as
	3mm	cherry or maple.
		Steel washer
	steel screw
	Hardwood mounting beams		O.S. radial motor mount
			(cast aluminum)

Use mounting screws of a diameter (between 3mm) appropriate to engine size (see table left).

9

THROTTLE LINKAGE

•Before connecting the throttle-lever / servo linkage, make sure that no part of the linkage interferes with the internal structure of the aircraft or wiring, etc., when the throttle is fully open or fully closed.

•Set the throttle lever linkage so that the throttle rotor is (a) fully open when the transmitter throttle stick is fully advanced and (b) fully closed when the throttle stick is fully retarded.

Adjustment of the throttle rotor opening at the idling position can then be made with the throttle trim lever on the transmitter.

(Select throttle-lever and servo-horn hole positions that will avoid excessive pushrod travel causing the throttle to bind at either end.)

Note:

When adjusting the throttle lever angle, relative to the rotor,hold the rotor at about half-way between the open and closed positions while loosening and tightening the fixing screw, otherwise the rotor, rotor guide screw,throttle stop screw or carburettor body may become burred and damaged.

SILENCER

The exhaust outlet of the silencer can be rotated to any desired position in the following manner:

Assembly screw

Cone baffle

Turn to requlred position

Exhaust outlet

Exhaust pressure nipple

Locknut

1)Loosen the locknut and assembly screw.

2)Set the exhaust outlet at the required position by rotating the rear part of the silencer.

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

NOTE :

The standard expansion-chamber type silencer is quite effective, but reduces power to some degree.

10