User Manual

ManualsBrandsOS Engines ManualsHelicopters105HZ-R DRS 1.05 Helicopter Engine

Table Of Contents

Dimensions (mm)

THREE VIEW DRAWING

ENGINE EXPLODED VIEW

ENGINEN PARTS LIST

RUNNING-IN ("Breaking-in")

ADJUSTMENT

CARE AND MAINTENANCE

Please pay attention to the matters described

below to ensure that your engine serves you well

in regard to performance, reliability and long life.

As previously mentioned, it is vitally important to

avoid operating the engine in conditions where dust,

disturbed by the propeller, may be deposited on the

engine and enter its working parts.

Remember to keep your fuel container closed to

prevent foreign matter from contaminating the fuel.

Install a fuel filter to prevent foreign matter in the fuel

container from entering the fuel tank. O.S. Super

Filters (L) and (S) are available as optional extras.

Install an in-line fuel filter between the tank and

carburetor to prevent foreign matter in the tank from

entering the carburetor.

If these precautions are neglected, restriction of fuel

flow may cause the engine to cut out, or the fuel/air

mixture to become too lean causing the engine to

overheat.

Clean these filters periodically.

The use of modern high-performance alcohol based

model engine fuels, while promoting cooler running,

improved anti-detonation combustion and increased

power, have the disadvantage of causing corrosion

due to the acid by-products of combustion.

The use of nitromethane in the fuel can also

contribute to the problem.

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 fuel supply while the engine is still running

at full throttle, then expel as much fuel residue as

possible by turning the engine over 5-10 seconds

with the electric starter.

Finally, inject some after-run oil through the glowplug

hole and turn the engine over several times by hand.

Type of screw

C…Cap Screw

The specifications are subject to alteration for improvement without notice.

CARBURETOR PARTS LIST

CARBURETOR EXPLODED VIEW

(55500003)

(71605100)

(71608001)

(71607100)

071503

http://www.os-engines.co.jp

6-15 3-Chome Imagawa Higashisumiyoshi-ku

Osaka 546-0003, Japan

TEL. (06) 6702-0225

FAX. (06) 6704-2722

O.S. GENUINE PARTS & ACCESSORIES

(72403050)

(71531000)

(

)

NON-BUBBLE WEIGHT

SUPER FILTER

LOCK WASHER

(

10set

)

GLOWPLUG

No.10

(

Former A5

)

No.8

No.7

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.

Starting procedure is as follows:

Make sure that plug element glows red, and install

the plug in the cylinder head.

STARTING

Open

Opening and closing of the Needle-Valve

Turn the needle clockwise to close the needle-valve,

and turn the needle counter-clockwise to open the

needle-valve as shown in the sketch.

High Speed needle-valve:

approx. two half turns open from the fully closed

position. (Note: If a different muffler is used, this

setting may require readjustment)

Idle Mixture Control Screw:

at basic position when the engine leaves the factory.

one turn open from the fully closed position.

Medium Speed needle-valve:

Checking the rotating direction of the starter

Make sure that the starter rotates to the direction

shown in the sketch. If the direction is reverse,

reverse the leads on battery.

Preparation of the starter

Install the starting shaft to the starter securely.

Improper installation will allow the shaft to swing

creating a dangerous situation.

High Speed

needle-valve

Idle Mixture Control Screw:

Medium Speed needle-valve:

Inserting the starter shaft

Insert the starting shaft into the shaft cup securely.

Priming

Check the movement of all the controls after

switching on both the transmitter and the receiver.

Then, fully open the throttle valve without heating

the plug. Turn the engine with an electric starter

until the fuel comes into the carburetor inlet.

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 shaft after

making sure the rotation of the starter shaft stops.

Preparation of starting

Hold the rotor head by hand so that rotor cannot rotate

when the engine is Started. Also, steady the model

with a foot on the landing gear skid.

Make sure that the transmitter throttle stick is at the

fully closed position and the throttle trim at center

position, and make sure that idle-up switch on the

transmitter is off.

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. It is 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.

NOTE:

If the throttle response is poor or the engine stops

due to a temporarily over-rich mixture immediately

after the engine is started, pinch the fuel line for

one or two seconds until the engine r.p.m.

increase and the engine runs steadily.

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 materrials, only a very short

and simple running-in procedure is required and can

be carried out with the engine installed in the model.

Main needle is set two and half turns open from fully

closed position and the medium speed needle is set

one turn open from fully closed position when the

engine leaves the factory.

It is expected with these needle settings the engine

may run rich. During running-in, hover the model

making sure the engine runs rich.

Also, during running-in since the mixture is rich, you

may feel uneven engine rpm and more fuel

consumption.

In the next section, needle adjustments to optimum

position from running-in position are explained.

Be sure to run the engine a little on the rich side so

that if will have a long life expectancy.

Please observe the following before beginning to

make any adjustment.

The general course of adjustment procedure is

shown in the ADJUSTING CHART and is correct

for a fuel containing 20% lubricant and 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, require the High-Speed

Needle Valve to be readjusted accordingly. The type

and percentage of lubricant used is also a factor here,

as noted later in these instructions.

This carburetor is not equipped with a throttle

stop screw. Instead, idle speed is adjusted by

means of the throttle trim lever on the transmitter.

High-Speed Needle Valve.

Turn this approximately 30 degrees (3 to 4 clicks) at a

time, when making initial adjustments; then in steps

of approximately 15 degrees (1 to 2 clicks) when

making final adjustments.

Medium-Speed Needle Valve.

Turn approximately 30 degrees (3 to 4 clicks) at a time.

Idle Mixture Control Screw.

Turn approximately 5 degrees at a time. It turns

approximately 90 degrees both sides from the center.

Turn left to enrich the idle mixture and turn right to

lean the idle mixture.

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, advance the throttle

trim lever slightly to increase the idle rpm.

Then open the throttle sufficiently to 'float' the model

above the ground. 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 5 degrees. lf the mixture is extremely

rich, engine rpm will become unstable: opening the

throttle will produce a great deal of smoke and rpm

may drop suddenly or the engine may stop.

ADJUSTMENT PROCEDURE

This condition may also be initiated by an excessively

prolonged warming-up period. lf, on the other hand,

the mixture is too Iean, this wiIl be indicated by a

marked lack of exhaust smoke and a tendency for the

engine to cut out when the throttle is opened. ln this

case, turn the Mixture Control Screw counter-clockwise

5 degrees to enrich the mixture.

Having provisionally set the idle mixture, the next

step is to adjust the mixture for hovering flight.

Hover the model and actuate the throttle to observe

response over the medium speed range. lf the engine

smokes excessiveIy and throttle response is poor,

the mixture is too rich ; in which case, land the model

and turn the High-Speed Needle Valve clockwise. Do

not close the High-Speed NeedIe Valve more than

the recommended initial adjustment (3 to 4 clicks) at

a time, keeping it a little on the rich side at this stage.

DO NOT touch the Medium Speed Needle Valve.

lf, on the other hand, hovering is not stable and

response to the throttIe is over-sensitive, or if the

engine tends to overheat, this indicates that the

mixture is too lean and should be corrected by turning

the High-Speed Needle Valve counter-clockwise.

After about 10 seconds of idling, open the throttle to

'float' the model. lf the transition is smooth, the idle

mixture is O.K. If the symptoms of either rich or Iean

running are observed, readjust the Idle Mixture

Control Screw accordingly.

NOTE: With this carburetor, neither the Idle Mixture

Control Screw adjustment, nor the Medium Speed

Needle Valve adjustment will have any effect on

mixture strength when the throttle is fully (or

almost fully) open.

Throttle Opening

Fully Closed

1/3

2/3 Fully Open

Fuel Flow

Maximum

Minimum

Adjustment range of Idle Mixture

Control Screw

Adjustment range of Medium

Speed Needle Valve

Needle Valve too

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.

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 running at

medium speeds. DO NOT touch the High-Speed

Needle Valve.

Now adjust the High-Speed Needle Valve to achieve

the best performance when the model is flying at full

throttle. lf, at full throttle, acceleration is poor, the

exhaust unduly smoky and the model fails to reach

expected straight line speed, the mixture is too rich

and the High-Speed 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 model immediately and

readjust thw High-Speed Needle Valve to a richer

setting.

Having now found the optimum setting for the

High-Speed Needle Valve, re-check the engine's

idle performance, fine tuning the Idle Mixture Control

Screw, if necessary, to perfect the idle.

It is at this point that the Medium Speed Needle

Valve, previously set one turn open, may be brought

into operation. Open the Medium Speed Needle

Valve 30 degrees, or 3-4 clicks, then fine tune until

the optimum hovering performance is obtained. If on

the other hand, hovering reveals rich running, close

the Medium Speed Needle Valve gradually until the

optimum hovering performance is obtained.

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

changes to the Main (High-Speed) Needle Valve

occasionally, to take account of differences in climatic

condisitions.

However, as previously mentioned, the use of a

different fuel, particularly one containing more, or less,

nitromethane and / or a different type or proportion of

lubricating oil, is likely to call for some modification to

the High-Speed Needle-Valve adjustment.

As a safety measure, it is advisable to increase the

High-Speed Needle Valve setting by an extra half-turn

counter-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.

CARBURETOR CLEANLINESS

Remove this with

an 8mm wrench

Dirt and foreign matter

mostly accumulate here

The correct functioning of the carburetor depends on

its small fuel orifices remaining clear. The minute

particles of foreign matter that are present in any fuel

can easily partially obstruct these orifices and upset

mixture strength so that engine performance becomes

erratic and unreliable. It is recommended 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 carburetor and, furthermore, that this filter is

frequently cleaned to remove foreign matter that

accumulates on the filter screen. Finally, occasionally

remove the needle-valve holder from the carburetor as

shown in Picture and extract any remaining foreign

matter that may have lodged in the location shown in

Picture below.

When the engine is not to be used for some months

(for example, as between flying seasons), a

worthwhile precaution is to remove it from the

airframe and, after washing off the exterior with

alcohol (not gasoline nor kerosene), remove

carefully the carburetor with intake pipe, glow plug

and all silicone tubing and put them safely aside.

Then, immerse the engine in a container of alcohol.

Rotate the crankshaft while the engine is immersed.

If foreign matter is visible in the alcohol, rinse the

engine again in clean alcohol. Finally, shake off and

dry the alcohol, and inject some after-run oil in the

glowplug hole and rotate the crankshaft several

times by hand.

Reinstall the carburetor with intake pipe and

glowplug on the engine and keep it in a dry place

after putting in a vinyl bag.

(72146000)

POWERBOOST PIPE 90

POWERBOOST PIPE 105

(71530530)

91/105/GT15

CRANKSHAFT CLAMP

(71531010)

(

)

NON-BUBBLE WEIGHT

(71520100)

O.S. SPEED RACING TOOLS SETS

O.S. SPEED PLUG WRENCH

(71520100)

(72145000)

79871055

79871120

79871150

M2.6x18

M3x10

M3x15

CAP SCREW SETS

(

10pcs./sets

)

Code No.

Size Pcs. used in an engine

Cylinder Head Retaining Screw (6pcs.)

Cover Plate Retaining Screw (4pcs.)

Retainer Screw (1pc.)

Heatsink Head

Head Gasket (0.2mm)

Cylinder Liner

Piston Ring

Piston

Piston Pin

Piston Pin Retainer (2pcs.)

Connecting Rod

Carburetor Complete 61G

Propeller Nut

Thrust Washer

Crankshaft Ball Bearing (Front)

Carburetor Retainer Assembly

"O" Ring

Crankcase

Crankshaft Ball Bearing (Rear)

Crankshaft

Cover Gasket

Cover Plate

Nipple (No.1)

Glow Plug No.8

Check Valve

Head Gasket (0.2mm)

Head Gasket (0.1mm)

Velocity Stack

Set Screw M3x3

No.

Description

Code No.

1-1

12-1

28704000

28704160

28703100

29203400

28703200

26606008

27917000

29505010

29088040

45010002

46120000

26731002

29081720

45566310

28701000

27930000

28702000

29061410

28707010

22681953

71608001

72403070

28704160

28704161

28712000

26381501

The specifications are subject to alteration for improvement without notice.

4-1

4-2

4-3

11-1

11-2

11-3

11-4

C.M2.6x7

9-1

9-2

9-3

10-1

9-4

C.M2x5

3-1

6-1

C.M3x8

1-1

Type of screw

C…Cap Screw

42.8

26.2

UNF 5/16-24

88.7

56.4

4- 4.2

Throttle Lever Assembly

Retaining Screw (10pcs.)

Carburetor Rotor

Rotor Guide Washer

Retaining Screw (10pcs.)

Mixture Control Valve Assembly

"O"Ring (L) (2pcs.)

"O"Ring (S) (2pcs.)

"O"Ring (L) (2pcs.)

Rotor Guide Screw

Carburetor Body

Thermo Insulater

Mixture Control Screw

Mixture Control Valve Stopper

Needle Valve Assembly

(Main Needle)

Needle Assembly

"O"Ring (2pcs.)

Needle Valve Holder Assembly

Ratchet Spring

Reguretor Assembly

Fuel Inlet (Nipple No.1)

Needle Valve Assembly

Needle Assembly

"O"Ring (2pcs.)

Needle Valve Holder Assembly

Ratchet Spring

Carburetor Rubber Gasket

1-1

3-1

4-1

4-2

4-3

6-1

9-1

9-2

9-3

9-4

10-1

11-1

11-2

11-3

11-4

29085140

79871110

29088250

25881220

79871020

29088320

27881810

27881800

27881820

45581820

29088140

27984900

27881330

27681340

29181900

29085910

24981837

29181940

26711305

29088800

22681953

29088980

29085910

24981837

27381940

26711305

27915000

C.M3x10

C.M3x15

1-1

12-1

C.M2.6x18

No.

Description

Code No.

The specifications are subject to alteration for improvement without notice.

Displacement

Bore

Stroke

Output

Practical R.P.M.

Weight

(Engine)

SPECIFICATIONS

17.17 cc / 1.048 cu.in.

29.0 mm / 1.142 in.

26.0 mm / 1.024 in.

3.8 ps / 3.75 hp / 15,000 r.p.m.

2,000-16,500 r.p.m.

608.4 g / 21.46 oz.