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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.

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Summary of Contents for MAX-15CV-A

Page 1: ...erein 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 MAX 15CV A 25...

Page 2: ...E STARTING 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 GENUINE O S PARTS ACCESSORIES ENGINE EXPLODED VIEWS ENGINE PARTS LISTS CARBURETOR EXPLODED VIEWS PARTS LISTS ENGINE THREE VIEW DRAWING 2 6 7 8 9 10 11 11 12 1...

Page 3: ...e 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 co...

Page 4: ... 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 f...

Page 5: ...aring 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...

Page 6: ... 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...

Page 7: ... 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 Warn...

Page 8: ...each 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 ...

Page 9: ...LATION OF THE CARBURETTOR 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 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 1 2 Rotate the retainer nut gently...

Page 10: ...X 32SX Code No 71908410 Make sure that the mounting beams are parallel and that their top surfaces are in the same plane Front view Side view Top surfaces are not in the same plane Opposite beam Top surfaces are not in the same plane Re align the surfaces as necessary Engine does not rest firmly CORRECT INCORRECT Top surfaces are in the same plane Tighten second nut firmly down onto first nut Tigh...

Page 11: ...ttle to bind at either end 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 the required position by rotating the rear part of the silencer Re tighten the assembly screw followed by the locknut THROTTLE LINKAGE SILENCER 1 2 3 NOTE The standard expansion chamber type silencer is quite ef...

Page 12: ...er a burn Reminder Suggested fuel tank capacities are listed opposite These will allow 12 13 minute flights Locate the fuel tank so that the top of the tank is 5 10mm 1 4 3 8 above the level of the needle valve Be sure to use a pressurized fuel system by connecting the muffler pressure nipple to the vent pipe of the fuel tank Suggested Fuel Tank Capacities 15CV A 25FX 32SX approx 100cc approx 200c...

Page 13: ... 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 as when When to replace the glowplug Filament surface has roughened and turned white Filament coil has become distorted Foreign matter has adhered to filament or ...

Page 14: ...ar to it Select by practical tests the most suitable fuel from among the best quality fuels available in your country for model use For the best performance a fuel containing 5 to 20 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 essentia...

Page 15: ... settings Two mixture controls are provided on these engines Type of Carburetor 15CV A 25FX 32SX 10K 20D 20F The Mixture Control Valve carburetor This meters fuel flow at part throttle and idling speeds to ensure reliable operation as the throttle is opened and closed The Mixture Control Valve is factory set for the approximate best result First run the engine as received and readjust the Mixture ...

Page 16: ...fuel container to the fuel tank Fuel bulb Manual Electric Fuel pumps Resistance coil nichrome wire Adjust applied voltage by changing the position of clip on resistance coil until glowplug element is glowing bright red Battery leads Raise voltage to increase brightness Lower voltage to reduce brightness Warning Very hot Never touch the nichrome wire while the battery is connected 1 5 volt heavy du...

Page 17: ...t is of precision made and sturdy construction so that the spinner shell cannot loosen when the starter is used Close the throttle 1 2 3 4 5 Open the throttle approx one quarter This is to avoid unnecessarily high r p m when the engine starts Turn needle valve clockwise to close for leaner mixture Turn needle valve counter clockwise to open for richer mixture Mark Close Open Fully closed position ...

Page 18: ...g overheated and damaged RUNNING IN Breaking in All internal combustion engines benefit from extra care when they are run for the first few timesknown as running in or breaking in This 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 finali...

Page 19: ...um setting referring to MIXTURE CONTROL VALVE ADJUSTMENT section and SUBSEQUENT READJUSTMENT section Slowly advance the throttle to its fully open position then gradually close the needle valve until the exhaust note begins to change 4 cycle to 2 cycle At this point disconnect the battery from the glowplug taking care that the battery leads or glowplug clip do not come into contact with the rotati...

Page 20: ...te Maximum rpm setting Lean STARTING Rich needle valve setting when starting the engine The engine may stop if the battery leads are disconnected from the glowplug while the engine is running rich Engine stops R e v o l u t i o n s s t a r t t t o d e c r e a s e t o d e 6 7 1 2 5 4 3 Intermittent high pitched two stroke note superimposed on low four stroke sound Note Although this is a two stroke...

Page 21: ...nds Does the engine stop Apply full throttle Does the engine regain full power immediately OK Refer to the next section Re set the idling position at a little higher r p m Set the throttle opening by means of the throttle trim on the transmitter so that the lowest practical speed without risk of the engine stopping is obtained The position where the lowest possible r p m with steady running is obt...

Page 22: ...ture Control Screw counter clockwise 90 to positively enrich the idle mixture then turn the screw clockwise gradually until the engine regains full power cleanly when the throttle is reopened Carry out adjustments patiently until the engine responds quickly and positively to the throttle control Note Mixture Control Valve adjustments should be made in steps of 15 30 initially carefully checking th...

Page 23: ...ing 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 ...

Page 24: ... 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 engin...

Page 25: ...05300 O S GLOW PLUGS O S GENUINE PARTS ACCESSORIES SPINNER NUT 20824005 23024008 23024009 M5 1 4 28 1 4 28 L 15CV A 20 25 RE 25FX 32SX Code No Size Type of Engine LONG PROPELLER NUT SETS Code No Size Type of Engine SILENCER EXTENSION ADAPTORS Code No Type of Engine Silencer SILENCER EXHAUST ADAPTORS Code No Type of Engine Silencer PROPELLER NUT SETS FOR TRUTURN SPINNERS 73101020 24 ...

Page 26: ...000 71521000 55500002 25FX 32SX M3 23325030 E 3030S 32SX Code No Size Type of Engine SUPER SILENCERS Size Code No Type of Engine SUPER FI LTER NON BUBBLE WEIGHT LOCK WASHER 10Sets LONG SOCKET WRENCH WITH PLUG GRIP 25 ...

Page 27: ...EXPLODED VIEW 15CV A Type of screw C Cap Screw F Flat Head Screw N Round Head Screw S Set Screw 1 2 3 4 5 6 7 8 9 0 q w e r C M2 6x12 M M2 6x8 e 1 e 2 e 3 e 4 e 5 S 3x3 26 ...

Page 28: ...et Set Crankshaft Crankshaft Ball Bearing Rear Crankcase Crankshaft Ball Bearing Front Drive Hub Propeller Washer Propeller Nut Carburetor Retainer Carburetor Type 10K Connecting Rod Piston Pin Cylinder Piston Assembly Cylinder Head Code No Glow Plug A3 2 1502 000 2 1230 000 2 1501 020 2 2631 019 2 1507 100 2 1507 000 2 1514 010 2 1408 000 2 1109 005 2 0810 007 2 1481 700 2 1581 000 2 1205 040 2 1...

Page 29: ...EXPLODED VIEW 25FX 32SX Type of screw C Cap Screw F Flat Head Screw N Round Head Screw S Set Screw r e 7 e 6 e 5 e 4 e 3 e 2 e 1 e w q 0 9 8 7 6 5 2 5 1 5 4 3 2 1 C M2 6X12 S M3X3 C M2 6X7 N M3 5X5 28 ...

Page 30: ...7381940 26711305 22413009 23325020 22681957 23325320 22625404 Description Retaining Screw 2pcs Assembly Screw Exhaust Pressure Nipple E 3030 Silencer For 32SX 892 Silencer For 25FX Screw Set Ratchet Spring Needle Valve Holder Assembly Set Screw O Ring For Needle 2pcs Needle Nipple No 1 Cover Plate Body Cover Plate Assembly Gasket Set Crankshaft Crankshaft Ball Bearing Rear Crankcase Crankshaft Bal...

Page 31: ...or Rubber Gasket Carburettor Retaining Screw 22681430 22681419 22681220 22681600 22481506 22681140 22681320 22681953 22615000 23081706 No Code No Description CARBURETOR 20D 25FX Type of screw C Cap Screw F Flat Head Screw N Round Head Screw S Set Screw Specifications are subject to alteration for improvement without notice CARBURETOR 10K 15CV A Throttle Lever Assembly Carburettor Rotor Mixture Con...

Page 32: ... Washer Carburetor Rubber Gasket Carburetor Retaining Screw 22781401 22781420 22781411 23481200 23481650 26781506 23482100 24881824 45581820 22681953 22615000 23081706 No Code No Description MAX 15CV A THREE VIEW DRAWING Displacement Bore Stroke Practical R P M Power output Weight 2 49 cc 0 152 cu in 15 2mm 0 598 in 13 7mm 0 539 in 2 500 19 000 r p m 0 5 bhp 18 000 r p m 170g 5 99 oz SPECIFICATION...

Page 33: ...G Displacement Bore Stroke Practical R P M Power output Weight 4 07 cc 0 2485 cu in 18 0mm 0 7087 in 16 0mm 0 630 in 2 500 19 000 r p m 0 84 bhp 18 000 r p m 248g 8 75 oz SPECIFICATIONS Dimensions mm 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 2 000 22 000 r p m 1 2 bhp 18 000 r p m 270g 9 5 oz SPECIFICATIONS 32 ...

Page 34: ...ights reserved Printed in Japan U N EQUALLED QUALITY PRECISION PERFORMAN C E ESTABLISHING THE STANDARDS OF EXCELLENCE 110101 TEL 06 6702 0225 FAX 06 6704 2722 6 15 3 Chome Imagawa Higashisumiyoshi ku Osaka 546 0003 Japan URL http www os engines co jp ...

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