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20

STARTING THE ENGINE & RUNNING-IN ('Breaking-in)

PRESSURIZED FUEL SYSTEM

!  

Before  starting  the  engine,  always  check  the 
tightness of all the screws and nuts especial-
ly  those  of  joint  and  movable  parts  such  as 
throttle  arm.  Missing  retightening  the  loose 
screws  and  nuts  often  causes  the  parts 
breakage that is capable of harming you. 

Never  run  your  vehicle  without  installing  the  air 
cleaner. Dust and dirt that may otherwise be drawn 
into the engine will rapidly shorten its life.

The  somewhat  violent  changes  of  vehicle  attitude 
that  occur  in  off-road  running,  combined  with  the 
fact  that,  in  buggy  type  cars,  the  fuel  tank  is  often 
located  some  distance  from  the  carburetor,  means 
that fuel 'head' at the carburetor can vary and upset 
running.Therefore,it  is  recommended  that  a  muffler 
pressurized fuel feed system be used.

Running- in is a procedure for an engine to come 
close  to  actual  running  conditions  (fuel,  r.p.m., 
engine temperature, etc.). 
Excessively  rich  running  and  prolonged  low 
speed running should be avoided.  Prolonged low 
speed running and low temperature running may 
result  in  the  oil  in  the  fuel  forming  varnish  that 
can  result  in  the  piston  /  liner  becoming  stuck 
together.

Please  do  not  run  on  a  public  street,  this 

could  cause  serious  accidents,  personal 

injuries and/or propetry damage.
Please  do  not  run  near  pedestrians  or  small 

children.
Please do not run in small or confined areas.

Please do not run where loud noises can disturb 

others, such as hospitals and residential areas.

While Operating

RUNNING-IN ('Breaking-in)

21

!  

Lay the chassis on a stand and start the engine so 
that the tires are not in contact with the ground.

The following procedure is suitable when a fuel 
containing up to 30% nitromethane is used.

Fill the tank completely with fuel.

Temporarily  remove  the  glowplug  to  check  that  it 
glows bright red when energized.

Glow Plug Igniter

Pliers

Element glows when
energized.

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

Fuel Pump

Fuel Tank

Do not hold a glowplug with fingers and use 
pliers when checking the brightness.  Do not 
have your face close to the glowplug or boiled 
fuel remaining in the coil will burn you.

stand

NOTE:

Be careful not to damage the plug threads when 
holding a glowplug with pliers.

Summary of Contents for MAX-12TG

Page 1: ...he vehicle radio control equipment etc are accessible for checking at the same time JAPAN 1 2 5 6 7 8 9 10 11 12 13 15 16 17 18 19 20 26 27 30 31 34 35 37 38 45 46 49 50 52 53 56 CONTENTS SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O S ENGINE ENGINE CONSTRUCTION NOTES WHEN APPLYING AN ELECTRIC STARTER INSTRUCTIONS BASIC ENGINE PARTS TOOLS ACCESSORIES etc STANDARD ACCESSORIES CARBURETOR CONTROLS IN...

Page 2: ... extreme circumstances even fatal injury These cover the many other possibilities generally less obvious sources of danger but which under certain circumstances may also cause damage or injury 3 WARNINGS Model engine fuel is poi sonous Do not allow it to come into contact with the eyesormouth Alwaysstore it in a clearly marked con tainer and out of the reach of children Model engine fuel is also h...

Page 3: ...rm is secure For their safety keep all onlookers especially small children well back at least 20 feet or 6 meters when preparing your model for running 5 NOTES To stop the engine fully retard the throttle stick and trim lever on the trans mitter or in an emergency cut off the fuel supply by pinching the fuel delivery line from the tank Warning Immediately after a glowplug ignition engine has been ...

Page 4: ...reach operating temperature Near TDC Slight taper When the engine is cold When the engine is hot 7 NOTES WHEN APPLYING AN ELECTRIC STARTER Do not over prime This could cause a hydraulic lock and damage the engine on application of the electric starter If over primed remove glowplug close needle valve and apply starter to pump out surplus fuel Cover the head with a rag to prevent any pumped out fue...

Page 5: ...dling the engines are equipped with a newly designed 12E or 12D carburetor An O S No 8 glowplug is also supplied with the engines The 12E and 12D engines have mild and smooth accelerating characteristics most suitable for sport running Recoil starter incorporated versions which eliminate the need for a separate electric starter and starter battery are also available MAX 12TG P with 12E carburetor ...

Page 6: ...del engine fuel is also highly flammable Keep it away from open flame excessive heat sources of sparks or anything else which might ignite it Do not smoke or allow anyone else to smoke near to it GLOWPLUG IGNITER Commercialy available handy glowplug heater in which the glowplug battery and battery leads are integrated 11 FUEL PUMP For filling the fuel tank a simple poly ethylene squeeze bottle wit...

Page 7: ...13 CARBURETOR CONTROLS The Needle Valve Adjusted at the factory Three adjustable controls are provided on this carburetor For adjusting the mixture strength when the throttle is fully open The Throttle Stop Screw Adjusted at the factory For setting the minimum idle speed For adjusting the mixture strength at part throttle and idle speed to obtain steady idling and smooth acceleration to mid speed ...

Page 8: ...ts carburetor lightly fit into the intake boss Secure it as follows Rotate the retainer screw gently until it stops then tighten a further 60 90 Do not overtighten the screw as this will damage the carburetor body 1 Rotate the retainer nut gently until it stops Tighten a further 60 90 Fuel Inlet Needle Holder Ball Link Retaining Screw Loosen the retainer screw rotate the carburetor to its correct ...

Page 9: ...ormance maintained by careful use i e Install a plug suitable for the engine Use fuel 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 With a glowplug engine ignition is initiated by the application of a 1 5 volt power source When the battery is disconnected t...

Page 10: ...bearers when the engine mount edges interfere with the engine Do not chamfer the engine File 19 JAPAN NOTE When spacers are supplied joined in pairs see sketch separate them as shown Either face may be placed downwards Avoid forcing the screws Secure with locknuts If the bottom of the recoil starter housing would otherwise touch the car chassis install the engine mount spacers supplied between the...

Page 11: ...d low speed running and low temperature running may result in the oil in the fuel forming varnish that can result in the piston liner becoming stuck together Please do not run on a public street this could cause serious accidents personal injuries and or propetry damage Please do not run near pedestrians or small children Please do not run in small or confined areas Please do not run where loud no...

Page 12: ... case of the 12E carburetor Approx 1mm open factory setting Common to 12D 12E carburetors 23 Fuel Deliver fuel into the carburetor Fuel tank side Note Check the throttle opening at idle before installing an air cleaner After the engine is started be sure to install an air cleaner If the fuel tank is equipped with a choke button push the button to send the fuel to the carburetor If not apply an ele...

Page 13: ...arts first allow it to operate in short runs at the very rich starting settings with the glowplug battery still connected and the driving wheels clear of the ground The rich mixture will under these conditions provide adequate lubrication and cooling indicated by profuse smoke from the exhaust It is vitally important to set the throttle at the correct position before attempting to start the engine...

Page 14: ...el have been consumed Note In the event of any major working parts e g piston cylinder liner assembly being replaced or the fuel being changed especially to high nitro fuel the complete running in should be repeated Warning Do not touch rotating parts engine and silencer when stopping the engine as they become very hot and contact with them may result in a serious burn To stop the engine close the...

Page 15: ...ning the Metering Needle or Mixture Control Screw counter clockwise 15 Adjust high RPM running Adjust medium and low RPM running Carry out adjustment by 15 degrees at a time for both closing and opening 29 With the optimum mixture control position light smoke is visible during high speed running and the engine rpm increases smoothly during acceleration Remember that if the engine is operated with ...

Page 16: ...anges in fuel formula gear ratio clutch engagement point and muffler Also needle setting may vary to atmospheric conditions within the day Readjust it according to actual engine running 31 TROUBLE SHOOTING Symptom Cause Corrective action Engine fails to fire Fuel tank is empty Fuel not reaching the engine Fill the tank with fuel and repeat Priming procedure Glowplug element is burnt out Glowplug b...

Page 17: ...comes stable Air bubbles in fuel Install O rings to the tank screws to prevent bubbles 33 Cause Corrective action Cause Corrective action Unstable idle Unsuitable glowplug Use suggested glowplug in the instructions Unsuitable fuel Do not use extremely high nitro or low oil content fuel Extremely light flywheel Use heavier flywheel Silencer is disconnected or has play Install silencer securely Not ...

Page 18: ...ind and is connected correctly Metering needle or mixture control screw closed too far Open the metering needle or mixture control screw a little 35 CARE AND MAINTENANCE Do not forget to clean the filters regularly to remove dirt and lint that accumulate on the filter screens Also clean the carburetor itself occasionally At the end of each operating session drain out any fuel that may remain in th...

Page 19: ...mance to become erratic and unreliable O S Super Filters large and small are available as optional extras to deal with this problem One of these filters installed to the pickup 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 carburetor Dirt and dust may lodge in ma...

Page 20: ...1020 21411010 21931000 21412020 21411400 21417000 23763000 71608001 21427200 MAX 12TG ENGINE PARTS LIST The specifications are subject to alteration for improvement without notice Description Code No No Heatsink Head Cylinder Piston Assembly Piston Pin Piston Pin Retainer 2pcs Connecting Rod Carburetor Complete Type 12E Carburetor Retainer Assembly Propeller Nut Drive Hub Crankshaft Ball Bearing F...

Page 21: ... 73008000 73008100 73008200 21923000 71608001 21427200 72404000 MAX 12TG X ENGINE PARTS LIST The specifications are subject to alteration for improvement without notice Heatsink Head Cylinder Piston Assembly Piston Pin Piston Pin Retainer 2pcs Connecting Rod Carburetor Complete Type 12E Carburetor Retainer Assembly Propeller Nut Drive Hub Crankshaft Ball Bearing Front Crankcase Crankshaft Ball Bea...

Page 22: ... 10 11 12 13 14 15 21414000 21413000 21536000 21817000 21415000 21418000 21428000 25381701 22631020 21411010 21931000 21412000 21411400 21417000 23763000 71608001 21427200 Heatsink Head Cylinder Piston Assembly Piston Pin Piston Pin Retainer 2pcs Connecting Rod Carburetor Complete Type 12D Carburetor Complete Type 12E Carburetor Retainer Assembly Crankshaft Ball Bearing Front Crankcase Crankshaft ...

Page 23: ...008000 73008100 73008200 21923000 71608001 21427200 72404000 MAX 12TG PX ENGINE PARTS LIST The specifications are subject to alteration for improvement without notice Heatsink Head Cylinder Piston Assembly Piston Pin Piston Pin Retainer 2pcs Connecting Rod Carburetor Complete Type 12D Carburetor Retainer Assembly Crankshaft Ball Bearing Front Crankcase Crankshaft Ball Bearing Rear Crankshaft Gaske...

Page 24: ...28100 22481506 21428200 21283210 22681419 21481420 21982630 27881820 22615000 12E CARBURETOR PART LIST The specifications are subject to alteration for improvement without notice Description Code No No Needle Valve Assembly O Ring 2pcs No 14 Universal Nipple Assembly Throttle Stop Screw Carburetor Body Rotor Spring Carburetor Rotor Dust Cover Throttle Lever Throttle Lever Fixing Nut Mixture Contro...

Page 25: ... 21881950 21982620 22781800 21418100 21982210 21538500 22781800 21982520 23818430 22615000 12D CARBURETOR PART LIST The specifications are subject to alteration for improvement without notice Description Code No No Needle Valve Assembly O Ring 2pcs No 14 Universal Nipple Assembly Throttle Stop Screw O Ring 2pcs Carburetor Body Slide Valve Metering Needle Assembly O Ring 2pcs Dust Cover Ball Link N...

Page 26: ...e 72106460 72106172 Manifold Spring M1003SC Left side exhaust Spring connect type O S GENUINE PARTS ACCESSORIES 72106600 22826140 72106042 Tuned Silencer T 1050SC L52 Tuned Silencer Assembly Exhaust Seal Ring 2pcs Joint Spring 3pcs Spring connect type Left side exhaust 72106500 72106510 72106310 72106320 72106400 72106410 21427200 21427200 72106520 72106360 72106400 21427200 72106530 72106370 7210...

Page 27: ...R AIR CLEANER 203 203 Filter Element 4pcs Engine Mount Spacer 72404000 Super Air Cleaner 202 202 Cleaner Body 202 Filter Element 4pcs Off road Type 72103310 21427200 2pcs Super Joint Tube 15 Exhaust Seal Ring 53 2 1 cc 0 128 cu in 13 8 mm 0 543 in 14 0 mm 0 551 in 5 000 30 000 r p m 0 7 ps 0 71 hp 28 000 r p m 212 8 g 7 5 oz SPECIFICATIONS 12TG THREE VIEW DRAWING Displacement Bore Stroke Practical...

Page 28: ...M Power output Weight Dimensions mm JAPAN M5x0 8 25 4 39 34 6 40 9 13 11 31 4 4 3 3 77 1 55 2 1 cc 0 128 cu in 13 8 mm 0 543 in 14 0 mm 0 551 in 5 000 30 000 r p m 0 7 ps 0 71 hp 28 000 r p m 211 3 g 7 45 oz SPECIFICATIONS 12TG P THREE VIEW DRAWING Displacement Bore Stroke Practical R P M Power output Weight Dimensions mm 12TG P W 12D JAPAN JAPAN UNEF1 4 28 25 4 39 15 1 34 9 29 5 11 31 4 4 3 3 77 ...

Page 29: ...Displacement Bore Stroke Practical R P M Power output Weight Dimensions mm JAPAN JAPAN 25 4 39 34 6 34 9 29 5 11 31 4 4 3 3 UNEF1 4 28 77 1 C Copyright 2006 by O S Engines Mfg Co Ltd All rights reserved Printed in Japan 60091800 061105 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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