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24

SUBSEQUENT STARTING PROCEDURE

SUBSEQUENT READJUSTMENT

Once the optimum needle-valve setting has been es-
tablished (see page 21, Needle-valve adjustment dia-
gram) the procedure for starting may be simplified as 
follows.

Open the needle-valve one half-turn (180

°

) from 

the optimum setting.

Set the throttle one-quarter open from the fully  
closed position, energize the glowplug and apply 
the electric starter. When the engine starts, re-
open the throttle and re-adjust the needle-valve to 
the optimum setting.

When re-starting the engine on the same day, 
provided that atmospheric conditions have not 
changed significantly, it may be practicable to re-
start the engine on its optimum(running) setting.

Once the engine has been run-in and the 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 conditions.
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 may 
also require compensating carburetor readjustments.

Note: 

1.

2.

25

CARBURETOR CLEANLINESS

ENGINE CARE AND MAINTENANCE

At the end of each operating session, drain out any 
fuel that may remain in the fuel tank.

Next, energize the glowplug and try to 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 re-
sidue 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. 

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

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

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.
O.S.'Super-Filters'(large and small ) are available, as 
optional extras, to deal with this problem. 
One of these filters, fitted to 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 needle-valve. 
Do not forget to clean the filters regularly to remove 
dirt and lint that accumulate on the filter screen. 
Also, clean the carburetor itself occasionally.

Note: 

1.

2.

3.

Summary of Contents for MAX-46AX

Page 1: ...for checking at the same time 1 CONTENTS SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O S ENGINE INTRODUCTION 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 CONTROLVALVE ADJUSTMENT REALIGNMENT ...

Page 2: ...sonous 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 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 C...

Page 3: ...ssary 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 an...

Page 4: ...er compression WITHOUT the glowplug battery being reconnected Remember this if you wish to avoid the risk of a painfully rapped knuckle 7 This engine 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 The needle val...

Page 5: ...valve unit through 90 and re attach it to the bracket in the required position see sketch right Vertical position Factory position Cover plate fitting holes Needle Valve unit Needle Valve unit attachment screws Needle Valve Assembly Bracket 1 2 Cover plate Retaining Screw 9 INSTALLATION OF THE ENGINE Rigid hardwood e g maple At least 15mm 5 8 At least 15mm 5 8 O S radial motor mount Available as a...

Page 6: ...e 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 Throttle Lever Fixing Screw 11 The exhaust outlet of the silencer can be rotated to any desired position in the following manner Loosen the locknut and assembly screw Set the exhaust outlet at...

Page 7: ... containing a moderate percentage of nitromethane unless more is essential for racing events Do not run the engine too lean and do not leave the battery connected while adjusting the needle However plug life can be extended and engine performance maintained by careful use i e Apart from when actually burned out a plug may need to be replaced because it no longer delivers its best performance such ...

Page 8: ...T 18 lubricant by volume Some fuels containing coloring additives tend to deteriorate and may adversely affect running qualities Once a satisfactory fuel has been selected and used for a while it may be unwise to needlessly change the brand or type In any engine a change of fuel may cause carbon deposits in the combustion chamber or on the piston head to become detached and lodged elsewhere with t...

Page 9: ...nce twin leads with special glowplug connectors as shown on the right are commercially available 17 12V Battery Starter 6 Fuel tank For installation in the model a 300cc 10 6oz tank is suggested 7 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...

Page 10: ... allows the working parts to mate together under load at operating temperature Therefore it is vitally important to complete the break in before allowing the engine to run continuously at high speed and before finalizing carburetor adjustments However because O S engines are produced with the aid of the finest modern precision machinery and from the best and most suitable materials only a short an...

Page 11: ... to arrive at the optimum setting Optimum needle setting 1 Optimum needle setting 2 21 20 45 Needle valve adjustment diagram This diagram is for reference purposes only Actual needle positions may differ from those shown To stop the engine close the throttle completely to cut off fuel air supply Note Practical best optimum needle valve setting Exhaust note starts to change Disconnect battery leads...

Page 12: ...ontrol Screw clockwise 15 30 If the mixture is excessively 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 excessively prolonged idling If on the other hand the mixture is too lean this will be indicated by a marked lack of exhaust smoke and a tendency for the engin...

Page 13: ...nsating carburetor readjustments Note 1 2 25 CARBURETOR CLEANLINESS ENGINE CARE AND MAINTENANCE At the end of each operating session drain out any fuel that may remain in the fuel tank Next energize the glowplug and try to 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 re sidue by rota...

Page 14: ...shaft Ball Bearing F Crankcase Crankshaft Ball Bearing R Crankshaft Gasket Set Cover Plate Needle Stay Needle Valve Unit Assembly Needle Assembly O Ring 2pcs Set Screw Ratchet Spring Needle Valve Unit Body Needle Valve Unit Retaining Screw Screw Set Glow Plug A3 E 3010 Silencer Assembly Pressure Fitting No 7 Assembly Screw Retaining Screw C M3x35 2pcs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 1...

Page 15: ...e specifications are subject to alteration for improvement without notice 6 7 8 N M3 5x6 1 2 3 4 5 1 1 1 2 2 1 1 1 1 1 2 2 2 1 3 4 5 6 7 8 24681410 22681419 22781420 24681610 22781800 24681200 24681100 45581820 22681953 46215000 25081700 No Code No Description 29 No 8 71608001 A5 71605100 73101020 23024009 1 4 28 L 73101000 1 4 28 71913100 72200080 25425020 873S O S GLOW PLUGS O S GENUINE PARTS AC...

Page 16: ...00 79870040 M4 25425600 M4 55500003 SILENCER EXTENSION ADAPTORS 31 7 45cc 0 455cu in 22 0mm 0 866in 19 6mm 0 772in 2 000 17 000r p m 1 65ps 16 000r p m 375g 13 2oz 114g 4 02oz Displacement Bore Stroke Practical R P M Power output Weight SPECIFICATIONS Dimensions mm THREE VIEW DRAWING E 3010 Silencer Assembly JAPAN 3 7 4 UNF1 4 28 38 1 44 4 119 4 27 2 60 4 7 24 8 36 3 17 5 17 8 67 4 48 100 5 35 51 ...

Page 17: ...ts reserved Printed in Japan 090300 TEL 06 6702 0225 FAX 06 6704 2722 6 15 3 Chome Imagawa Higashisumiyoshi ku Osaka 546 0003 Japan U N E Q U A LLED QUALITY PRECISION PERFOR M A N C E E S T A BLISHING THE STANDARDS OF EXCELLE N C E URL http www os engines co jp ...

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