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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 2-6 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.

Summary of Contents for 15LA-S

Page 1: ...ontained 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 ...

Page 2: ... BEFORE STARTING PLUMBING AND FUEL TANK POSITION ADVICE ON SELECTION OF FUEL GLOW PLUG PROPELLER STARTING THE ENGINE RUNNING IN Breaking in TROUBLE SHOOTING WHEN THE ENGINE FAILS TO START CARE AND MAINTENANCE ENGINE EXPLODED VIEW PARTS LIST THREE VIEW DRAWING OPTIONAL PARTS ACCESSORIES 2 6 7 8 9 10 12 12 14 22 14 20 21 22 20 23 24 27 30 28 29 9 10 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: ...hearing Such noise is also likely to cause annoyance to others over a wide area Fit 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 c...

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: ...olvents Such decolorization does not affect engine perfor mance however Cylinder head Venturi Silicone Tube Crankshaft Propeller nut Propeller washer Drive Hub Crankcase Needle valve Cover Plate Fuel outlet Fuel inlet Glowplug Connect the short length of fuel tubing supplied securely between the fuel outlet and the fuel inlet In the event of the tube becoming damaged it should be replaced with a s...

Page 9: ...ew Top surfaces are in the same plane Re align the surfaces as necessary INCORRECT Top surfaces are not in the same plane Opposite beam Top surfaces are not in the same plane Engine does not seat firmly Rigid hardwood e g maple Installation in the model A typical method of beam mounting is shown below left O S radial motor mount Available as an optional extra part See parts list Make sure that the...

Page 10: ...ion by rotating the rear part of the silencer 3 Re tighten the assembly screw followed by the locknut The standard silencer is quite effective but reduces power to some degree INSTALLATION OF SILENCER Assembly screw Cone baffle Turn to requlred position Exhaust outlet Locknut Exhaust pressure nipple Modelenginesgenerateconsiderableheat Do not touch any part of your engine until it has cooled Conta...

Page 11: ...alve Assembly Bracket 1 2 BEFORE STARTING Tools accessories etc The following items are necessary for operating the engine 1 Fuel Model glowplug engine fuel of good quality preferably containing a small percentage of nitromethane See Advice on selection of fuel glowplug and propeller 2 Glowplug O S A3 glowplug is installed in the engine 3 Propeller Suggested size is 8X4 15LA S 9X6 25LA S 11X5 40LA...

Page 12: ...olyethylene squeeze bottle with a suitable spout is all that is required Alternatively one of the purpose made manual or electric fuel pumps may be used to transfer fuel directly from your fuel container to the fuel tank 9 Fuel can filter Fit a filter to the outlet tube of your refuelling container to prevent entry of foreign matter into the fuel tank R C clunk tank installation For tightening glo...

Page 13: ... and for improved flexibility Note that even a small quantity of nitromethane 3 5 will improve flexibility making the needle valve adjustment less critical and improving throttle response Use only materials of the highest purity Synthetic oils are permissible but are less tolerant of a lean run than castor oil If therefore a synthetic lubricant is used in the fuel readjust the needle valve to a sl...

Page 14: ... will require in flight experimentation Aerobatic Sport 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 Running in Reminder GLOWPLUG An O S A3 glowplug is installed in the engine Other recommended O S plugs are Nos 8 and A5 Carefully fit plug finger tight before final tightening with the correct size plug wrench ...

Page 15: ...NG THE ENGINE Preparations 1 Installing the glowplug Installthewasherontheglowplugand screw carefully into cylinder head making sure that it is not cross threaded before tightening firmly Glow plug Washer 2 Installing the propeller First mount the propeller on the engine by tightening the prop nut or spinner nut lightly and make sure of the position where compression is felt turning the propeller ...

Page 16: ...S Super Filter Re connect delivery tube to engine after tank is filled Disconnect delivery tube from the fuel inlet and connect it to the tubing from the fuel pump Do not let dirt or dust enter fuel can Fuel model glow plug engine fuel 1 2 Close Open Close Open Open the needle valve 3 turns for 15LA S 1 turns for 25 40 46LA S in the direction of arrow from the closed position 4 Opening and closing...

Page 17: ...ld model securely when starting Starter Assistant Assistant should hold the model so that it cannot move forward when the engine starts Be careful not to be hit by propeller Glowplug battery Place as far to the rear as possible 8 Heat glowplug Starting battery Connect battery leads as shown polarity is immaterial Turn the engine for 3 to 4 seconds by an electric starter without connecting glowplug...

Page 18: ... action will cause an excess quantity of fuel to be drawn into the cylinder and result in hydraulic lock that may damage the engine BEWARE of the rotating propeller 10 Engine starts If the engine does not start refer to the TROUBLE SHOOTING CHART In the interests of safety keep your face and other parts of the body away from the vicinity of the propeller Warning Since a control line engine is star...

Page 19: ... needle valve is closed beyond the initial readjustment the r p m of the engine will be increased and a continuous high pitched exhaust note only will be heard Key to the needle valve adjustment Turn 20 30 at a time Turn the needle valve 20 30 in the direction of arrow and wait momentarily for the change of r p m After the r p m of the engine increases turn the needle valve another 20 30 and wait ...

Page 20: ... only Actual needle positions may differ from those shown On starting from cold with the needle valve set at the rich starting position Take note of this position of the needle valve This will produce the practical best i e optimum rpm setting lower than maximum rpm A light grey exhaust emission may be observed Now re open needle valve 20 30 maximum rpm is reached and will fall off or engine will ...

Page 21: ...r the first few times known as running in or breaking in This is because the working parts of a new engine take a little time to settle down after being subjected to high temperatures and stresses However because O S engines are made with the aid of the finest modern precisionmachineryandfromthebestandmostsuitable materials only a very short and simple running in procedure is required and can be c...

Page 22: ...ocedure referring to 6 Priming Sluggish rotation Glowplug battery discharged Glowplug element is burned out Something wrong with battery leads Engine flooded due to excessive priming Insufficient priming Engine fails to fire TROUBLE SHOOTING WHEN THE ENGINE FAILS TO START Four key points For quick reliable starting the following four conditions are required 1 Good compression 2 Adequate glow at gl...

Page 23: ... Repeat priming procedure referring to 6 Priming Close needle valve half turn 180 and wait for several minutes then re start Priming is not necessary Make sure that tank is filled with fuel Check that there is not something wrong with fuel tubing kinked or split Check that carburettor is not clogged with dirt Close the needle valve a little Change fuel or glowplug Incorrect heating of glowplug Ove...

Page 24: ...ine at the conclusion of a flying session it may cause corrosion The best practice is to disconnect the delivery tube from the venturi while the engine is running Remaining fuel in the tank should also be drained off Clean the exterior of the engine with a clean cotton cloth If this is not done oil and dirt will burn onto the outside of the engine each time it is run and the engine will soon becom...

Page 25: ... q 3 q 5 q 4 q 2 q 1 N M3X12 25LA S M3 5 B M2 6X8 S 3X3 M M2 6X10 15LA S 9 8 7 6 e EXPLODED VIEW MAX 15 25LA S Type of screw C Cap Screw M Oval Fillister Head Screw F Flat Head Screw N Round Head Screw S Set Screw 24 ...

Page 26: ...00 21752000 21757000 21757100 21781970 21714100 21713000 21225000 22681957 22325300 21125409 22325020 22681957 22325310 22625404 22312000 26711305 24981837 26381501 Cylinder Head Cylinder Piston Assembly Piston Pin Connecting Rod Venturi Nozzle For Remote Needle Propeller Nut Propeller Washer Drive Hub Thrust Washer Crankcase Crankshaft Cover Plate Assembly Cover Plate Ratchet Spring Needle O Ring...

Page 27: ...2 1 9 7 6 8 0 w q r 1 r 2 r 3 r 4 r 5 r 6 N M3X8 N M3X12 S 3X3 e r t M3 5 Type of screw C Cap Screw M Oval Fillister Head Screw F Flat Head Screw N Round Head Screw S Set Screw EXPLODED VIEW MAX 40 46LA S 26 ...

Page 28: ...26381501 26711305 26582910 26582920 24013000 71605300 23325020 22681957 23325320 22625404 21381980 23302000 Cylinder Head Cylinder Piston Assembly Piston Pin Connecting Rod Venturi Nozzle For Remote Needle Propeller Nut Propeller Washer Drive Hub Thrust Washer Crankcase Crankshaft Gasket Set Cover Plate Needle Valve Assembly B racket Needle Valve Assembly Needle O Ring Set Screw Ratchet Spring Nee...

Page 29: ...1517 cu in 15 2mm 0 598 in 13 7mm 0 539 in 2 500 18 000 r p m 0 41 bhp 17 000 r p m 129 5g 4 56 oz MAX 15 25LA S THREE VIEW DRAWING Displacement Bore Stroke Practical R P M Power output Weight 25LA S SPECIFICATIONS Displacement Bore Stroke Practical R P M Power output Weight 15LA S SPECIFICATIONS 15LA Dimensions mm 28 ...

Page 30: ... 0 467cu in 23 0 mm 0 906in 18 4 mm 0 724in 2 000 16 000 r p m 1 2 bhp 15 000 r p m 263 5g 9 29oz MAX 40 46LA S THREE VIEW DRAWING Dimensions mm Displacement Bore Stroke Practical R P M Power output Weight 40LA S SPECIFICATIONS 46LA S SPECIFICATIONS Displacement Bore Stroke Practical R P M Power output Weight 29 ...

Page 31: ...024008 for 25LA S SUPER SILENCER SPINNER NUT LONG PROPELLER NUT SET BUBBLESS WEIGHT SUPER FILTER L SILENCER EXTENSION ADAPTORS GLOW PLUG LONG SOCKET WRENCH WITH PLUG GRIP 22325030 for 25LA S 73101000 for 25 46LA 72403050 71521000 71605300 E 2030S 23325030 for 40 46LA S E 3030S 4 1 M5 20824005 for 15LA S 28 L 4 1 23024009 for 40 46LA S A3 71531000 Bubble Eliminating Tank Weight 30 ...

Page 32: ...ghts reserved Printed in Japan U N EQUALLED QUALITY PRECISION PERFORMAN C E ESTABLISHING THE STANDARDS OF EXCELLENC E 110100 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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