O.S. engine MAX-91FX Setup guide

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.

●

SAFETY INSTRUCTIONS AND

WARNINGS ABOUT YOUR O.S. ENGINE

FEATURES OF FX SERIES ENGINES, BEFORE

INSTALLING THE ENGINE

BASIC ENGINE PARTS

NEEDLE-VALVE LOCATION

INSTALLATION OF THE ENGINE

THROTTLE LINKAGE, SILENCER

FUEL TANK LOCATION

GLOWPLUG

FUEL, PROPELLERS

MIXTURE CONTROLS

BEFORE STARTING

RUNNING-IN (Breaking-in)

IDLING ADJUSTMENT CHART

MIXTURE CONTROL VALVE ADJUSTMENT,

REALIGNMENT OF MIXTURE CONTROL VALVE

SUBSEQUENT STARTING PROCEDURE

SUBSEQUENT READJUSTMENT

CARBURETOR CLEANLINESS,

ENGINE CARE AND MAINTENANCE

ENGINE EXPLODED VIEWS &

ENGINE PARTS LISTS

CARBURETOR EXPLODED VIEWS

& PARTS LISTS

GENUINE O.S. PARTS &ACCESSORIES

ENGINE THREE VIEW DRAWINGS

MEMO

STARTING

CONTENTS

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.

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

Model engine fuel is poisonous. Do not

allow it to come into contact with the eyes

or mouth.Always store it in a

clearlymarkedcontainerand

out of the reach of children.

Never operate your engine in an en-

closed space. Model engines, like auto-

mobile engines, exhaust deadly carbon-

monoxide. 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.

•

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 also highly

flammable. Keep it away from open flame,

excessive heat, sources of sparks, or

anythingelsewhichmightignite

it.Donotsmokeorallowanyone

else to smoke, near to it.

•

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' recommenda-

tions, using appropriate screws and lock-

nuts.

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.

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.

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.

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

inanyway,unlessyouarehighlyexperienced

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.

•

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 glowplug-

ignition 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!

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.

With the 50SX, 61FX and 91FX, the needle-valve

assembly can be installed either horizontally or

vertically.

FEATURES OF FX SERIES ENGINES

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.

Note :

•

Carefully insert plug, with

washer, fingertight only, before

final tightening with the correct

size plug wrench.

BEFORE INSTALLING THE ENGINE

Installing the glowplug

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.

Connecting fuel tubing

Length

40¡46FX 54

56mm 61FX

91FX

56mm

62mm

Glow plug

Washer

50SX

46mm

Length

Glow Plug No.8, Silicone Tube, Instruction Manual

Common to accessories

50SX, 40/46FX

61FX

91FX

873 Silencer Assembly

E-4010 Silencer Assembly

E-4020 Silencer Assembly

Needle Valve Extension Cable

Type of engines Type of engines

The proce

dure for relocating the needle-valve vertically

is as follows:

As delivered from the factory, the MAX-61FX and

MAX-91FXRING have their needle-valve assembly

installed horizontally. However, if more convenient for

a particular installation, the needle-valve may be

reinstated vertically behind the cylinder. (See sketch

opposite.) Please note that the needle-valve knob

has a center hole and set-screw for the fitting of a

piano-wire extension (supplied with the 91FX) so that,

when relocated vertically, the extension enables

adjustments to be made without risk of burning one's

fingers on the cylinder head.

NEEDLE-VALVE LOCATION

BASIC ENGINE PARTS

Cylinder head

Carburetor

Silicone Tube

Crankshaft Propeller nut

Propeller washer

Drive Hub Crankcase

Needle valve

Cover Plate

Fuel outlet

Fuel inlet

Glowplug

Fuel inlet

Beam Mount

MAX-61FX

Throttle

Lever

Throttle Stop Screw

Using 8mm wrench, remove complete needle-valve

holder assembly including needle, from side of

cover plate.

Remove fuel inlet assembly from upper boss of

cover plate.

Transfer banjo type fuel inlet including washers, to

needle-valve holder and carefully screw complete

assembly into upper boss vacated by fuel inlet

assembly. Tighten very carefully.

Inlet Holder

Plug Screw (50SX/91FX)

Fuel Inlet

Needle-Valve

Assembly

Needle Extension

Inlet Holder

Fuel Inlet

Needle-Valve

Assembly

45mm

Fuel Inlet

Needle-Valve

Assembly Plug Screw (50SX/91FX)

Fuel Inlet

Needle-Valve

Assembly

Needle Extension

45mm

61FX

50SX/91FX

Use hexagon-head brass inlet holder (61FX) or

plug screw (50SX/91FX) to blank off side boss

vacated by needle- valve assembly.

This manual suits for next models

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