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BASIC POSITION  OF  MIXTURE  CONTROL  SCREW
(Mixture Control Valve)

Rich

Mixture Control Valve

MIxture Control Screw

Lean

As  delivered,  the  Mixture  Control  Screw  is 
positioned at approximately the center as shown in 
the  sketch.  Mixture  gets  lean  when  the  Mixture 
Control Screw is turned right, while mixture gets 
rich when the Mixture Control Screw is turned left.
With  a  model  helicopter,  adjustments  vary  with 
combined  various  factors  such  as  climatic 
conditions, fuel, muffler, main rotor, weight of the 
model,  gear  ratio,  etc.    Therefore  the  Mixture 
Control Screw position varies with each model and 
set- up, and it is normal if the Mixture Control Screw 
position is off the center.

89 degrees

When the triangle mark on the carburetor rotor meets 
the far right mark, the throttle is fully closed.  When 
the triangle mark meets the top mark, the throttle is 
fully open.  The range is 89 degrees.  You may use 
the other three marks as the reference marking of 
throttle opening to your preference when hovering.

WARNING!
Never  try  to  check  the  triangle  mark  position 
while the engine is running and rotor 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.

Carburetor Rotor

Carburetor Body

Fully closed
position

Fully opened position

As  shown  in  the  sketch,  the  carburetor  has 
graduation marks.

GRADUATIONS ON THE CARBURETOR BODY

21

!  

Be  sure  to  use  an  electric  starter  to  start 
the engine.

Fill the fuel tank with fuel. When filled, prevent the 
fuel  from  flowing  into  the  carburetor  with  a 
commercially available fuel stopper, etc.  Release 
the stopper before starting the engine.

1.

2.

Starting procedure is as follows:

WARNING
When  checking  the  plug  element  hold  the  plug 
with tools, such as pliers, etc.
Do not hold near your face or the fuel remaining 
in the filament may burn you.

Glow Plug Igniter

Pliers

Element glows when energized.

Replace the plug when the 
element does not glow or is 
burnt out. 

Make sure that plug element glows red, and install 
the plug in the cylinder head.

Never  fail  to  check  the  tightness  of  screws 
and  nuts,  especially  engine  mounting  and 
moving parts (e.g. throttle lever).

Be  sure  to  use  a  muffler  pressurized  fuel  feed. 
Use  the  same  fuel  as  you  intend  to  employ  for 
actual operation of your model.

STARTING

Summary of Contents for MAX-55HZ HYPER

Page 1: ...control equipment etc are accessible for checking at the same time 1 2 5 6 7 8 9 10 12 17 21 25 31 38 39 40 41 42 26 30 18 32 33 34 37 13 16 19 20 43 44 CONTENTS SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O S ENGINE NOTES ON INSTALLING COOLING FAN AND CLUTCH NOTES WHEN APPLYING AN ELECTRIC STARTER INSTALLATION OF THROTTLE SERVO NOTES ON HEATING THE GLOW PLUG INTRODUCTION ENGINE PARTS NAME BEFORE ...

Page 2: ... many other possibilities generally less obvious sources of danger but which under certain circumstances may also cause damage or injury 3 WARNINGS Never touch or allow any object to come into contact with the rotating parts Model engine fuel is poison ous 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 Mode...

Page 3: ... head down securely Take care that the glow plug clip or battery leads do not come into contact with rotating parts 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 5 NOTES Take care that loose clothing ties ...

Page 4: ...amaged Also do not insert a screw driver or the similar into the exhaust port It is recommended to use Crankshaft Clamp 3246 Code No 71530400 available as an optional tool 7 Do not grip the engine mounting beams with a vise or the crankcase will be distorted which will result in engine breaking Vise Beam Mount Notes on installing cooling fan and clutch ...

Page 5: ...surplus fuel Cover the head with a rag to prevent pumped out fuel from getting into your eyes 9 F J J F 28 34 27 33 A B 9 0 9 0 A B Linking the throttle servo to the carburetor Link the throttle servo to the carburetor using the throttle lever supplied Throttle control rod A and B should be equal length Set the linkage so that the servo output lever and throttle lever are parallel when the throttl...

Page 6: ... No 8 Instruction manual This is a high performance engine expressly designed for 50 size helicopters Since engine mounting and muffler mounting bolt patterns are the same as the 50SX H Hyper it can be installed in the existing 50 size helicopters Newly designed 40L carburetor enables to adjust idling hovering and high speed independently Close to 60 size power offers wide power range suitable for...

Page 7: ...ting the glowplug may be either a large heavy duty 1 5volt dry cell Ni cd battery or glowplug Igniter 1 5 volt dry cell 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 commercially available Battery leads glowplug Igniter Make sure glowpl...

Page 8: ...ow anyone else to smoke near to it 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 Manual Electric Install a filter to the outlet tube of your refueling container to prevent entry of foreign matter into fuel tank O S Super Filters large and small are available as optional extras O S Super Filter Fue...

Page 9: ...aces are not in the same plane Engine does not rest firmly Make sure that only the under surfaces of the engine s mounting lugs are in contact with the engine mount INSTALLATION OF THE ENGINE 17 GLOWPLUG CARBURETOR INSTALLING THE GLOWPLUG Install washer on glowplug and insert carefully into Heatsink head making sure that it is not cross threaded before tightening firmly Glow plug Washer As deliver...

Page 10: ...t before final tightening with the correct size plug wrench 19 With a fixed wing model power failure is rarely a serious threat to the safety of the aircraft since it can usually glide down to a safe landing In a helicopter on the other hand it is vitally imporant that the engine keeps running and that there is a quick and reliable response to the throttle in order to ensure safe ascent and descen...

Page 11: ...ile the engine is running and rotor 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 Carburetor Rotor Carburetor Body Fully closed position Fully opened position As shown in the sketch the carburetor has graduation marks GRADUATIONS ON THE CARBURETOR BODY 21 Be sure to use an electric starter to sta...

Page 12: ...ing creating a dangerous situation High Speed needle valve Idle Mixture Control Screw Medium Speed needle valve 23 5 Inserting the starter shaft Insert the starting shaft into the shaft cup securely 6 Priming Without energizing the glowplug open the throttle a little from the idle position Turn the engine over using the starter until the fuel is seen to reach the carburetor Stopping the engine Ful...

Page 13: ...o contact with the rotating rotor 25 All internal combustion engines benefit to some degree from extra care when they are run for the first few times known as running in or breaking in This allows the working parts to mate together under load at operating temperature However because O S engines are made with the aid of the finest modern precision machinely and from the best and most suitable mater...

Page 14: ...or is not equipped with a throttle stop screw Instead idle speed is adjusted by means of the throttle trim lever on the trans mitter ADJUSTMENT 27 As a safety measure first check the transmitter controls including the throttle stick and trim lever positions and hold the main rotor securely before starting the engine Warm the engine by allowing it to idle for about 30 seconds If the engine stops ad...

Page 15: ...oo far open Needle Valve too far closed High Speed Needle Valve Setting varies according to the curve When satisfactory hovering flight has been achieved land the modeI again and re check the engine s idle qualities 29 Now re check hovering performance It may be found that with the High Speed Needle Valve now set for optimum full throttle performance hovering will reveal symptoms of slightly lean ...

Page 16: ...unter clockwise prior to establishing the 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 or changes to the main rotor and its pitch angles may also require compensating carburetor readjustments 31 ADJUSTING CHART High Speed Needle Va...

Page 17: ...m 33 Do not close the needle valve and mixture control valve too far as this will cause a lean setting and over heating of the engine This can in turn create nitromethane oxide leading to internal rusting of the engine Always adjust the needlevalve slightly on the rich side of peak rpm Do not leave unused fuel in the engine at the conclusion of a day s flying Accepted practice is to cut off the fu...

Page 18: ...Incorrect carburetor settings Return the needle valve and mixture control valve to basic position Incorrect servo linkage Reconnect linkage after setting servo at neutral Reverse rotating direction of electric starter Mare sure the engine rotates counter clockwise seen from crankshaft side 35 Symptom Cause Corrective action Engine fires intermittently but does not run Insufficient fuel in the tank...

Page 19: ...nected or disconnected Check the connections and secure them Fuel tubing from tank to is split or broken Replace the tubing 37 Symptom Cause Corrective action Symptom Cause Corrective action Poor response Deteriorated glowplug Replace glowplug Incorrect carburetor settings Readjust low r p m range with metering needle and mixture control valve Poor r p m drop Too much throttle opening at idle Lowe...

Page 20: ... 14 15 16 17 18 25804000 25804160 25803100 27703400 25803200 25806000 25217000 25205000 25881000 23210007 46120000 26731002 25881700 45566310 25801000 25830000 25802000 25804170 25807000 25613000 71608001 Heatsink Head Head Gasket 0 2mm Cylinder Liner Piston Ring Piston Piston Pin Piston Pin Retainer 2pcs Connecting Rod Carburetor Complete 40L Propeller Nut Thrust Washer Crankshaft Ball Bearing Fr...

Page 21: ...he specifications are subject to alteration for improvement without notice CARBURETOR PARTS LIST No Description Code No Throttle Lever Assembly Throttle Lever Retaining Screw 2pcs Carburetor Rotor Rotor Guide Washer Rotor Guide Washer Retaining Screw Mixture Control Valve Assembly O Ring L 2pcs O Ring S 2pcs O Ring 2pcs Rotor Guide Screw Carburetor Body Mixture Control Screw Mixture Control Valve ...

Page 22: ...N BUBBLE WEIGHT S 71605100 No 10 Former A5 71608001 No 8 71607100 No 7 71530400 3246 CRANKSHAFT CLAMP POWER BOOST Pipe 55 M3x35 Cap Screw 2pcs Nipple 1pc Spring Washer 2pcs 43 37 7 11 5 37 31 51 6 44 17 5 UNF1 4 28 18 3 51 6 25 72 6 54 JAPAN 52 36 38 47 8 93 cc 0 55 cu in 23 mm 0 91 in 21 5 mm 0 85 in 2 000 20 000 r p m 2 1 hp 17 000 r p m 408g 14 40 oz THREE VIEW DRAWING Displacement Bore Stroke ...

Page 23: ...right 2009 by O S Engines Mfg Co Ltd All rights reserved Printed in Japan 60092230 100903 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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