Operating Instructions Motor OS Max 25 LA II Glow -S08512354

Copyright 2018 by O.S. Engines Mfg. Co., Ltd. All rights reserved. Printed in JAPAN.
C
60093610 101800
http://www.os-engines.co.jp
As the needle-valve is closed slowly and gradually, the
engine r.p.m. will increase and a continuous
high-pitched exhaust note, only, will be heard. Close
the needle-valve 10-15 degrees and wait for the
change of r.p.m. After the engine r.p.m. increases turn
the needle-valve another 10-15 degrees and wait for
the next change of r.p.m. As the speed of the engine
does not instantly change with needle-valve
readjustment, small movements, with pauses between,
are necessary to arrive at the optimum setting.
Optimum needle setting (1)
Optimum needle setting (2)
Slowly advance the throttle to its fully open position,
then gradually close the needle-valve until the exhaust
note begins to change. (4-cycle to 2-cycle)
Needle-valve adjustment diagram
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 dirt and dust 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 dirt and dust 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 needlevalve 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.
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, 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 and glowplug on the engine
and keep it in a dry place after putting in a vinyl bag.
(71908100)
(71531010)
No.8
(71608001)
No.6 (Fomer A3)
O.S.GLOW PLUG
O.S. GENUINE PARTS & ACCESSORIES
RADIAL MOTOR MOUNT
SILENCER EXTENSION ADAPTORS
NON-BUBBLE WEIGHT (S)
(72403050)
SUPER FILTER
LOCK WASHER
(10sets)
(
L
)
(71521000)
LONG SOCKET WRENCH WITH PLUG GRIP
ENGINE EXPLODED VIEW & PARTS LIST
Type of screw
C...Cap Screw
CARBURETOR EXPLODED VIEW & PARTS LIST
Dimensions(mm)
THREE VIEW DRAWING
6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan
TEL. [phone]
FAX. [phone]
(6pcs./sets)
FANG NUT
The specifications are subject to alteration for improvement
without notice.
20-45
degrees
This diagram is for reference
purposes only.
Actual needle positions may
differ from those shown.
Note :
Practical best(optimum) needle-valve setting
Exhaust note starts to change.
Disconnect battery
leads from glowplug at
about this point.
Clear, high-pitched two-stroke
exhaust note
Maximum rpm
setting("Lean").
STARTING
"Rich" needle-valve
setting when starting
the engine.
The engine may stop if
the battery leads are
disconnected from the
glowplug while the
engine is running rich.
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Intermittent, high-pitched
two-stroke note
superimposed
on low "four-stroke"
sound.
1
2
3
4
5
6
7
No.7
(71607100)
No.
Code No.
Description
Type of screw
N...Round Head Screw S...Set Screw
The specifications are subject to alteration for improvement
without notice.
No.
Code No.
Description
(79870031)
M3
(55500002)
(22325100)
(71605300)
(23024008)
1/4-28
SPINNER NUT
CAP SCREW SETS
(
10pcs./sets
)
Code No.
Size
Pcs. used in an engine
Cylinder Head Retaining Screw (4pcs.)
Cover Plate Retaining Screw (4pcs.)
Cylinder Head
Head Gasket
Cylinder & Piston Assembly
Piston Pin
Connecting Rod
Carburetor Complete (Type 22F)
Propeller Nut (1/4-28)
Propeller Washer
Drive Hub
Thrust Washer
Crankcase
Crankshaft
Gasket Set
Cover Plate
Glow Plug No.6 (A3)
E-2030 Silencer Assembly
Assembly Screw
Pressure Nipple (No.7)
Silencer Retaining Screw (M3x27 2pcs.)
Needle Assembly
"O" Ring
Set Screw
Needle-valve Holder Assembly
Ratchet Spring
Fuel Inlet (No.1)
Roter Guide Screw
Carburetor Body
Air Bleed Screw
Carburetor Rotor
Throttle Lever Assembly (No.5)
Throttle Lever Retaining Screw
Carburetor Rubber Gasket
Carburetor Retaining Screw
Displacement
Bore
Stroke
Output
Practical R.P.M.
Weight
(Engine)
(Silencer)
SPECIFICATIONS
Note: Although this is a two-stroke engine it fires like a four-stroke at these rich needle-valve settings-i.e.
ignition of the fuel charge takes place at every fourth stroke of the piston instead of at every second stroke.
These engines are equipped with a throttle type
car-burettor which provides a wide range of engine
speed control. With the throttle lever linked to a
suitable servo in the model, movement of the throttle
control on the transmitter will enable engine r.p.m. to
be varied, proportionally, from idling speed to full
power. The carburettor of your engine has been
factory set for the approximate best results and no
adjustment (except to the needle-valve) should be
required provided that the fuel tank is correctly
located, as previously described. After the engine has
been run-in, check the operation of the throttle
according to the following chart. Re-adjust the controls
only when necessary.
CARBURETTOR
Start the engine.
Make sure that the throttle is
fully open.
Adjust the neede-valve.
Close the throttle gradually.
Find the idling position.
Fix the idling position.
Open the throttle fully.
Does the engine
regain full power?
Continue running at high speed
for 10 seconds.
Close the throttle.
Run at idling speed for 5 seconds.
Does the engine stop?
Apply full throttle.
OK
Refer to the CARBURETOR
AIR-BLEED ADJUSTMENT
Re-set the idling position
at a little higher r.p.m.
Set the throttle opening by means
of the throttle trim on the transmitter so
that the lowest practical speed, without
risk of the engine stopping,is obtained.
The position where the lowest possible
r.p.m. ,with steady running, is obtained.
20-30
˚ open from maximum r.p.m. setting.
Yes.
No.
Yes.
Engine
stops.
Engine
stops.
Engine
stops.
Does the engine regain
full power immediately?
CARBURETTOR AIR-BLEED ADJUSTMENT
Pre-Flight Check
Start engine and adjust needle-
valve as previously described.
Close the throttle gradually.
Find the idling position.
Hold the model.
Hold model level,
then slowly raise
its nose.
If revolutions increase.
If engine runs unevenly
or stops.
Immediately point
nose down, so that engine
runs steadily again.
Stop the engine.
Stop the engine.
Note: Stop engine by
pinching fuel delivery
tube. Do not touch
needle-valve.
Open air-bleed
screw.
Half turn at a
time.
Close air-bleed
screw.
Half turn at a
time.
Repeat the procedure while opening and closing the throttle until the best result is obtained.
Do not leave the glowplug connected to the batter
while adjusting the carburettor throttle.
approx.
15˚
approx. 15˚
Attention:
(
72200080
)
NEEDLE VALVE EXTENSION CABLE SET
M3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
1-1
1-2
2
2-1
3
4
5
6
7
8
8-1
9
10
1/4-28(L)
(23024009)
C.M3x12
2
1
3
4
5
6
7
12
13
10
11
8
9
C.M2.6x7
14
22554010
22564000
22553000
22606009
22405013
22381010
23210007
24009000
22558000
22020001
22551010
22302000
22364000
22307000
71605300
22325020
22325310
22681957
22625404
79871020
79871140
M2.6x7
M3x12
44281970
24981837
26381501
27381940
26711305
22681953
22581300
22381110
22381600
22381200
22081408
22081313
22615000
23081706
5
N.+M3.5x5
1
4
7
S.M3X3
3
8
8-1
N.+M3x6
9
10
1-1
1-2
2
2-1
6
N.+M2.6x7
4.07 cc / 0.248 cu.in.
18.0 mm / 0.709 in.
16.0 mm / 0.63 in.
0.6 ps / 0.59 hp / 15,000 r.p.m.
2,500-16,000 r.p.m.
197.0 g / 6.95 oz.
62.0 g / 2.19 oz.
76.6
70.7
4- 3.3
18
18
36
6.5
7.5
14
20.1
39.2
32
30.5
60
20.1
14.5
46.5
22
UNF1/4-28
17.3
68.3
44
29
26
23.1