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6

Notes on installing cooling   fan and clutch

Do not use a tool which 

locks  piston  when 

installing a cooling-fan 

and  clutch,  or  top  of 

the  piston  may  be 

damaged.  Also, do not 

insert a screw driver or 

the  similar  into  the 

exhaust port.

It  is  recommended  to  use  Crankshaft 

Clamp 7091 (Code No.71530500) available 

as an optional tool. 

It is made of durable engineering plastic 

and locks the crankshaft without risk of 

damage to any part of the engine.

Application is as follows:

Remove the crankcase rear cover plate from the 

engine and rotate the crankshaft to the bottom 

dead center (BDC) position.

Insert the crankshaft clamp so that its grooved 

portion surrounds the crankpin and lower end of 

the connecting rod and securely tighten the fan 

or clutch onto the crankshaft.

Insert this groove onto

the connecting rod.

BDC position

Rotate the crankshaft so that the

connecting rod comes to this position.

7

Note on installing the engine

Note on heating the glow plug 

Cooling  fan  cover  from

some helicopter  models

interferes  the heatsink 

head. In this case, cut out

the cover as illustrated.

Example

Cut out according to the heatsink head.

Heatsink head, crankcase and cover 

plate of the engine are treated with 

Alumite  which  does  not  conduct 

current.  Therefore,  when  heating  a 

glow plug, connect one lead to the 

glow plug and the other to the head 

of cover plate fitting screw.

First, heat the center plug and start the

engine. Then, heat the second plug while

running the engine at idle. When the

second plug is ignited, idling sound

changes. After confirming this change,

disconnect battery lead to the plugs. If

the idling mixture is rich, it is necessary

to heat the second plug for about 5-10

seconds to ignite. Carefully listen to the

idling sound to confirm the change.

Example

Summary of Contents for MAX-91SX-HRING C Spec PS VIPER

Page 1: ...LE SERVO CARE AND MAINTENANCE EXPLODED VIEW PARTS LIST O S GENUINE PARTS ACCESSORIES THREE VIEW DRAWING MEMO 7 8 13 16 30 10 36 22 24 24 27 29 32 35 37 38 It is of vital importance before attempting t...

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...

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 tri...

Page 4: ...oove onto the connecting rod BDC position Rotate the crankshaft so that the connecting rod comes to this position 7 Note on installing the engine Note on heating the glow plug Cooling fan cover from s...

Page 5: ...h torque type starter DO NOT however confuse tightness with the symptoms of hydraulic lock caused by an excess of fuel within the cylinder often the result of over priming Attempting to force the engi...

Page 6: ...the under surfaces of the engine s mounting lugs are in contact with the engine mount 11 ABOUT THE PUMP SYSTEM Please understand the pump construction before piping Pump functions in accordance with t...

Page 7: ...el in the pump Stop the fuel flow to the pump with the stopper and run the engine at idling to use out the fuel in the pump After stopping the engine rotate the engine by electric starter to eject fue...

Page 8: ...1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1...

Page 9: ...and connections carefully for any cracks on the tubes and loose connections as the engine runs ejecting excess fuel 17 4 Glowplug battery The power source for heating the glowplug may be either a lar...

Page 10: ...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 re...

Page 11: ...Ixture Control Screw Lean With a model helicopter adjustments may vary due to various factors such as climatic conditions fuel muffler main rotor weight of the model gear ratio etc 89 degrees When the...

Page 12: ...ating a dangerous situation 23 In case the engine does not stop Hold the rotor head and pinch the fuel line to stop the fuel supply If it still does not stop pull off the fuel line from the carburetor...

Page 13: ...15 30 nitromethane Bear in mind that fuels containing relatively large percentages of power boosting nitromethane operate at richer mixture settings than are needed for mild fuels and will therefore r...

Page 14: ...se at medium r p m e g hovering speeds is most important since this is a power range widely used in helicopter flight The optimum fuel air nixture strength at medium speeds is dependent on obtaining b...

Page 15: ...mostly accumulate here 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...

Page 16: ...re Close the High Speed Needle Valve Turn clockwise Land the model Idle for approx 10 seconds then reopen throttle to observe transition Float the model Idling OK Lean mixture Rich mixture High Speed...

Page 17: ...ide 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 1 Finally inje...

Page 18: ......

Page 19: ...881810 27881800 27881820 45581820 29084100 27881330 27681340 27081900 27981910 24981837 46181940 46181941 26711305 46181950 Ratchet Spring Needle Needle Valve Assembly Fuel Inlet Rotor Guide Screw O R...

Page 20: ...MP 10set Cap Screw Set M2 6x5 10pcs set 79871010 M3 5x10 79871070 7091 71530500 For 70SZ H 91SX H Needle Adjusting Screw 5pcs M2 6x5 41621100 37 THREE VIEW DRAWING Displacement Bore Stroke Practical R...

Page 21: ...d in Japan 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 LLEDQ U A LIT Y P R E C IS IO N P E R F O R M A N C...

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