Dimensions (mm)
THREE VIEW DRAWING
ENGINE EXPLODED VIEW
ENGINEN PARTS LIST
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
(55500002)
(71605100)
(71608001)
(71607100)
C
121401
Copyright 2013 by O.S. Engine Mfg. Co., Ltd. All rights reserved. Printed in CHINA.
http://www.os-engines.co.jp
6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan
TEL. (06) 6702-0225FAX. (06) 6704-2722
O.S. GENUINE PARTS & ACCESSORIES
(72403050)
(71531000)
(L)
NON-BUBBLE WEIGHT
SUPER FILTER
M3
LOCK WASHER (10set)
GLOWPLUG
No.10 (Former A5)
No.8
No.7
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.
POWERBOOST PIPE 55
POWERBOOST PIPE 55
3246
CRANKSHAFT CLAMP
(71531010)
(S)
NON-BUBBLE WEIGHT
(71520100)
O.S. SPEED PLUG WRENCH
79871055 M2.6x18
CAP SCREW SETS (10pcs./sets)
Code No.
Size
Pcs. used in an engine
Retainer Screw (1pc.)
Heatsink Head
Head Gasket
Cylinder Liner
Piston Ring
Piston
Piston Pin
Piston Pin Retainer (2pcs.)
Connecting Rod
Carburetor Complete 40L-R
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)
Screw Set
Glow Plug No.8
Check Valve
No.
Description
Code No.
The specifications are subject to alteration for improvement without notice.
Type of screw
C…Cap Screw
Throttle Lever Assembly
Retaining Screw (10pcs.)
Carburetor Rotor
Rotor Guide Washer
Mixture Control Valve Assembly
"O"Ring (L) (2pcs.)
"O"Ring (S) (2pcs.)
"O"Ring (L) (2pcs.)
Rotor Guide Screw
Carburetor Body
Mixture Control Screw
Mixture Control Valve Stopper
Needle Valve Assembly (Main Needle)
"O"Ring (2pcs.)
Needle Valve Holder Assembly
Needle Valve Holder
Ratchet Spring
Reguretor Assembly
Fuel Inlet (Nipple No.1)
Needle Valve Assembly
"O"Ring (2pcs.)
Needle Valve Holder Assembly
Ratchet Spring
Carburetor Rubber Gasket
The specifications are subject to alteration for improvement without notice.
(71530400)
(72144000)
(72147000)
(72144040)
EXHAUST GASKET SET 55HZ (3pcs.)
C.M3x15
2
3
4
5
6
7
8
9
10
11
12
14
15
19
13 12-1
C.M2.6x18
C.M3x8
16
17
18
1
1-1
1
1-1
2
3
4
5
6
7
8
9
10
11
12
12-1
13
14
15
16
17
18
19
25804010
25804160
25803100
27703400
25803200
25806000
25217000
25205000
25881010
23210007
46120000
26731002
25881700
45566310
25801000
25830000
25802000
25804170
25807010
22681953
25613000
71608001
72403070
3
4-1
4-2
4-3
4
5
6
7
8
12-1
13-1
13
12
C.M2.6x7
2
C.M3x8
1
1-1
14
10
9
C.M2x5
10-1
9-1
11-1
11
10-2
1
1-1
2
3
4
4-1
4-2
4-3
5
6
7
8
9
9-1
10
10-1
10-2
11
11-1
12
12-1
13
13-1
14
29085140
22826131
25881210
25881220
29085510
27881810
27881800
27881820
45581820
25881100
27881330
27681340
29085910
24981837
29181940
29181941
26711305
29088800
22681953
27981910
24981837
27381940
26711305
29015019
No.
Description
Code No.
Rotor Guide Washer
Retaining Screw (1pc.)
79871020 M2.6x7
CAP SCREW SETS (10pcs./sets)
Code No.
Size
Pcs. used in an engine
37.7
11.5
37
31
51.6
44
17.5
UNF1/4-28
18.3
51.6
25
72.6
54
52
36
38
47
Displacement
Bore
Stroke
Output
Practical R.P.M.
Weight
(Engine)
SPECIFICATIONS
8.93 cc / 0.55 cu.in.
23.0 mm / 0.91 in.
21.5 mm / 0.85 in.
2.1 ps / 2.07 hp / 17,000 r.p.m.
2,000-20,000 r.p.m.
429 g / 15.13 oz.
