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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.

Summary of Contents for Max-50SX-H Ring

Page 1: ...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: ... CARBURETOR CONTROLS STARTING RUNNING IN ADJUSTMENT SUBSEQUENT READJUSTMENTS CARBURETTOR 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 2 5 6 7 8 8 10 10 11 12 13 13 14 18 19 21 22 23 24 25 15 18 20 26 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: ... away from open flame excessive heat sources of sparks oranythingelsewhich might ignite it Do not smoke orallowanyoneelsetosmoke near to it 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 operate your engine in an en closed space ...

Page 5: ...diately after the 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 carburetor Use an electric starter The wearing of safety glasses is also strongly recommended Press ...

Page 6: ...t 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 engine has been run and is still warm conditions sometimes exist whereby it is just possible for the engine to restart when turned ...

Page 7: ...g 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 Note This is a high performance engine developed expressly for F3C M class helicopter competition utilizing 50 cubic inch engines The engine uses the same mounting hole spacing as the O S 46FX H RING making the tw...

Page 8: ...l 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 en...

Page 9: ...he engine mount Please note that crankcase volume of the 50SX H is a little larger than the 46FX H s If the crankcase body touches the mount chamfer the edges of the mount As delivered the engine has its carburetor lightly fitted into its intake boss Secure it as follows INSTALLATION OF THE CARBURETOR Retainer screw Carburetor Rubber Gasket 0 2mm gap Loosen the retainer screw rotate the carburetor...

Page 10: ...t Never touch the nichrome wire while the battery is connected 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 conve nience twin leads with special glowplug connectors as shown on the right are comme...

Page 11: ...ust be regarded as expendable 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 app...

Page 12: ...he 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 S...

Page 13: ...mooth 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 Two adjustable controls are provided on this carburetor Needle Valve Throttle Lever Mixture Control Valve MIxture Control Screw BASIC POSITION OF MIXTURE CONTROL VALVE Mixture Control Screw Th...

Page 14: ...otor is rotating or you may be hit by rotating rotor which results in serious injury Stop the engine and rotor before checking the triangle mark position Graduations on the carburetor body Carburetor Rotor Carburetor Body Fully closed position Fully opened position Opening and closing of the Needle Valve Turn the needle clockwise to close the needle valve and turn the needle counter clockwise to o...

Page 15: ...necessary to readjust the throttle linkage so that the carburetor rotor is fully closed when the throttle stick and throttle trim on the transmitter are fully pulled Down Stopping the engine Fully pull down the throttle trim on the transmitter Starting Connect the battery to the glowplug and start the engine by applying the starter When started switch off the starter and withdraw the starting shaf...

Page 16: ...nd 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 adjus ted by means of the throttle trim lever on the transmitter NOTE If the throttle response is poor or the engine stops due to a temporarily over rich mixture im mediately after the engine is started pinch the fuel line for o...

Page 17: ...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 B C 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 ...

Page 18: ...f at full throttle acceleration is poor the H I J K 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...

Page 19: ...haracteristics 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...

Page 20: ...d 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 ma...

Page 21: ...dle for approx 10 seconds then reopen throttle to observe transition Float the model Turn the Mixture Control Screw counter clockwise Idling OK Turn the Mixture Control Screw clockwise Lean mixture Rich mixture High Speed Flight Open the Needle Valve Turn counter clockwise Lean mixture Rich mixture L M Close the Needle Valve Turn clockwise High Speed Flight OK Fine tuning of hovering mixture Turn ...

Page 22: ...t its output arm and the throttle pushrod are as closely as possible directry in line with carburetor s throttle arm as shown Servo output arm Throttle control rod A and B should be equal of length Set the linkage so that the servo output arm and throttle arm become par allel when the throttle stick on the transmitter is at middle position If differential throttle movement is required make necessa...

Page 23: ...Type of screw C Cap Screw M Oval Fillister Head Screw F Flat Head Screw N Round Head Screw S Set Screw EXPLODED VIEW y t r e w q 0 9 8 7 6 5 4 3 2 1 C M3X15 C M3X8 C M2 6X18 1 i u 22 ...

Page 24: ... Assembly Carburetor Complete 40E Connecting Rod Piston Pin Cylinder Liner Heatsink Head No 25204000 25203100 25303400 25203200 25206000 25217000 25205000 25281000 23818190 23210007 27708010 27708200 46120000 26731002 23981700 25201000 26730010 25202000 25214000 25207000 25613000 71608001 Code No Description Piston Ring Piston Piston Pin Retainer Carburetor Sealing Washer Drive Washer Woodruff Key...

Page 25: ...1820 45581820 25281100 22681953 27881330 27681340 27981900 27981910 24981837 27381940 26711305 29015019 Carburetor Rubber Gasket Ratchet Spring Needle Needle Valve Assembly Fuel Inlet Rotor Guide Screw O Ring L 2pcs Carburetor Body Mixture Control Valve Assembly Carburetor Rotor Throttle Lever Retaining Screw Throttle Lever Assembly Description Code No O Ring S 2pcs O Ring L 2pcs Mixture Control S...

Page 26: ...847 in 2 000 20 000 r p m 1 8 bhp 17 000 r p m 413g 14 58oz THREE VIEW DRAWING Displacement Bore Stroke Practical R P M Power output Weight SPECIFICATIONS Dimensions mm 38 46 52 36 UNF1 4 28 61 24 8 56 70 5 18 5 37 37 7 11 44 51 6 31 Ø26 2 17 5 25 ...

Page 27: ...8001 71521000 L No 8 71605100 A5 72403050 71705000 55500002 LONG SOCKET WRENCH WITH PLUG GRIP SUPER FILTER O S GLOW PLUGS IN FLIGHT CONTROL NEEDLE VALVE LOCK WASHER 10set M3 O S GENUINE PARTS ACCESSORIES 26 ...

Page 28: ...eserved Printed in Japan 110103 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 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 ...

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