60092980_21xz-bver2_2.pdf – O.S. Engines 21XZ-B VII User Manual

Page 2

(71641300)

(71641400)

(71641500)

(72101272)

(72106137)

(22826140)

(72106042)

(72413000)

(72413200)

(71812000)

(71813000)

(72415000)

(72415200)

(72106192)

(72106190)

(22826140)

(72106042)

(72106480)

CARBURETOR ADJUSTMENT

Open

Needle Valve

Metering Needle

More fuel

Less fuel

More fuel

Less fuel

Run the vehicle (with throttle fully open) over the

longest available straight course a few times to

observe the model’s speed. Return the vehicle to the

starting point and close the Needle-valve 15°and

repeat the run, taking note of the improvement in

performance.

Continue with further runs, gradually reduce the

Needle-valve setting aiming to achieve the highest

straight-line speed (optimum position).

Remember, however, if the Needle-valve is closed too

far, the engine will overheat, accompanied by visibly

diminished exhaust smoke and the model will lose

speed. At this point, throttle down immediately, stop

the vehicle and reopen the Needle-valve 30~45°.

Carburetor adjustment should be carried out only after

the running-in has been completed.

After setting the Needle-valve at optimum position,

run the vehicle a few times at the straight line.

With the engine running, close the throttle and

allow it idle for about five seconds, then reopen the

throttle fully.

If, at this point, the engine puffs out an excessive

amount of smoke and the vehicle does not

accelerate smoothly and rapidly or even stops, it is

probable that the idle mixture is too rich. In this

case, turn the Metering needle clockwise 15~30°.

If, on the other hand, the engine tends to speed up

momentarily and then cut out abruptly when the

throttle is opened, the idle mixture is too lean. In

this case, turn the Metering needle counter-clockwise

15~30°.

CARE AND MAINTENANCE

The minute particles of foreign matter, that are present in

any fuel may, by accumulating and partially obstructing

fuel flow, cause engine performance 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.
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 the fuel tank. Afterwards,energize

the glow-plug and try to restart the engine, to burn off

any fuel that may remain inside the engine. Repeat this

procedure until the engine fails to fire. Do this while the

engine is still warm.

4. Then, inject some after-run oil into the engine, and

rotate the engine with an electric starter for 4 to 5

seconds to distribute the oil to all the working parts.

Note:

Do not inject after-run oil into the carburetor as

this may cause the O-rings inside the carburetor to

deteriorate. These procedures will reduce the risks

of starting difficulties or corrosion after a period of

storage.

Dirt and dust may lodge in marked places.

5. Finally, when cleaning the exterior of the engine, use

methanol or a household cleaning agent. Do not use

gasoline, kerosene, or any petroleum based chemical

which can damage silicone fuel tubing.

CHECKING THE ENGINE

If the engine will not develop normal performance after

long time running due to wearing of parts. It is suggested

to replace necessary parts when the following symptoms

are detected.

Engine sound changes and easily overheats.

Power has dropped extremely.

Idle is unstable and/or engine tends to stop at idle.

In most cases, ball bearings, cylinder & piston assembly,

connecting rod and/or crankcase have become worn.

Check the parts carefully and replace them if necessary.

O.S. GENUINE PARTS & ACCESSORIES

71410150

71410200

71410250

71410300

71411200

71411250

71412300

71413550

71413600

71413700

O.S. SPEED HEX WRENCH DRIVER 1.5
O.S. SPEED HEX WRENCH DRIVER 2.0
O.S. SPEED HEX WRENCH DRIVER 2.5
O.S. SPEED HEX WRENCH DRIVER 3.0
O.S. SPEED HEX BALL WRENCH DRIVER 2.0
O.S. SPEED HEX BALL WRENCH DRIVER 2.5
O.S. SPEED FLAT HEAD SCREWDRIVER 3.0
O.S. SPEED NUT DRIVER 5.5
O.S. SPEED NUT DRIVER 6.0
O.S. SPEED NUT DRIVER 7.0

O.S. SPEED DRIVER TOOLS

Code No.

Description

71414015

71414020

71414025

71414030

71414120

71414125

71414230

71414355

71414360

71414370

O.S. SPEED HEX WRENCH TIP ONLY 1.5
O.S. SPEED HEX WRENCH TIP ONLY 2.0
O.S. SPEED HEX WRENCH TIP ONLY 2.5
O.S. SPEED HEX WRENCH TIP ONLY 3.0
O.S. SPEED HEX BALL WRENCH TIP ONLY 2.0
O.S. SPEED HEX BALL WRENCH TIP ONLY 2.5
O.S. SPEED FLAT HEAD SCREWDRIVER TIP 3.0
O.S. SPEED NUT DRIVER TIP ONLY 5.5
O.S. SPEED NUT DRIVER TIP ONLY 6.0
O.S. SPEED NUT DRIVER TIP ONLY 7.0

Code No.

Description

The specifications are subject to alteration for improvement

without notice.

O.S. GLOW PLUG

(71520100)

(71415100)

(71415200)

(71415300)

O.S. SPEED CLUTCH WRENCH & ADJUSTER

O.S. SPEED FLYWHEEL KEY

O.S. SPEED FLYWHEEL PULLER

O.S. SPEED PLUG WRENCH

T-2060SC WNI TUNED SILENCER COMPLETE SET

Exhaust Seal Ring (2pcs.)

Joint Spring (3pcs.)

Header Pipe Spring (2pcs.)

T-2090SC TUNED SILENCER COMPLETE SET

(71812100)

(71801100)

(71813100)

(71801100)

SUPER AIR CLEANER 203

203 Filter Element (4pcs.)

(For MUGEN)

(For KYOSHO)

28XZ Hyper Flywheel MUGEN

Collet

28XZ Hyper Flywheel KYOSHO

Collet

T-2090SC Tuned Silencer Assembly

Exhaust Seal Ring (2pcs.)

Joint Spring (3pcs.)

(72101272)

(22826140)

(72106440)

M2000SC Exhaust Header Pipe Assembly

Header Pipe Spring (2pcs.)

Exhaust Seal Ring (2pcs.)

(72101272)

(22826140)

Header Pipe Spring (2pcs.)

Exhaust Seal Ring (2pcs.)

28XZ HYPER FLYWHEEL SET

SUPER AIR CLEANER 204

204 Filter Element (4pcs.)

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

Dimensions (mm)

THREE VIEW DRAWING

Specifications

Displacement

Bore

Stroke

PracticalR.P.M.

Output

Weight

79871020
79871055
79871180

M2.6x7
M2.6x18
M3x18

CAP SCREW SETS (10pcs./set)

Code No.

Size

Pcs. used in an engine

Cylinder Head Retaining Screw (4pcs.)

Cover Plate Retaining Screw (4pcs.)
Carburetor Retainer Retaining Screw (1pc.)

ENGINE EXPLODED VIEW

CARBURETOR EXPLODED VIEW

Type of screw

S...Set Screw

Type of screw
C...Cap Screw

ENGINE PARTS LIST

CARBURETOR PARTS LIST

The specifications are subject to alteration for improvement without notice.

CARBURETOR REDUCER

M2002SC EXHAUST HEADER PIPE ASSEMBLY

60092980 011401

The specifications are subject to alteration for improvement without notice.

Outer Head

Inner Head

Head Gasket (0.2mm)

Head Gasket (0.1mm)

Built-up Parts Set

Cylinder & Piston Assembly

Piston Pin

O.S. SPEED Piston Pin Retainer 4mm(6pcs.)

Connecting Rod

Carburetor Complete (Type 22B2)

Carburetor Retainer Assembly

"O" Ring (2pcs.)

Crankshaft Ball Bearing (Front)

Crankcase

Crankshaft Ball Bearing (Rear)

Crankshaft

Cover Gasket

Cover Plate

Glow Plug P3 (Turbo)

Exhaust Seal Ring (2pcs.)

O.S. SPEED Dust Cap Set For 12-30 Class

No. Code No.

Description

5-1

5-2

5-3

5-4

7-1

NEEDLE VALVE ADJUSTMENT

METERING NEEDLE ADJUSTMENT

THROTTLE STOP SCREW ADJUSTMENT

If the engine runs too fast with the throttle closed, the

throttle stop screw should be turned counter-clockwise

to allow the throttle opening to be reduced.

OPTIMUM MIXTURE CONTROL POSITION

With the optimum mixture control position, light smoke

is visible during high speed running and the engine rpm

increase smoothly during acceleration. Carry out

adjustment 1.~3. patiently until the engine responds

quickly and positively to the throttle control.

Remember that, if the engine is operated with the fuel/air

mixture slightly too lean, it will overheat and run

unevenly. As with all engines, it is advisable to set both

the needle-valve and metering needle slightly on the rich

side of the best rpm setting, as a safety measure.

Finally, beyond the normal break-in period, a slight

readjustment toward a leaner needle setting may be

required to maintain maximum performance.

Note:

Please regard the standard positions in the

instruction manual as just a guide. Positions will

vary due to the fuel and silencer used. In general,

if a fuel containing less nitromenthane is used, the

needlevalve will need to be closed further.

Remember, closing the needlevalve too far can

cause rusting and damage to the engine.

When storing the engine, install the cap on the exhaust

port, carburetor, etc. to prevent dust from entering the

engine.

INATALLING DUST CAPS

(23730050)

3.49 cc (0.213 cu.in.)

16.27 mm (0.641 in.)

16.8 mm (0.661 in.)

3,000-41,500 r.p.m.

2.6 ps / 2.56 hp / 34,000 r.p.m.

362 g (12.77 oz.)

31.6

UNF1/4-28

20.5

29.5

86.5

28.5

15.6

4- 3.3

CERAMIC REAR BEARING FOR 21

22414040

22424104

22014160

22014170

22423110

22423100

22016000

21817010

22425000

22282000

23981740

24881824

23731020

22411030

23730020

22412010

23107100

22417100

71641300

22826140
22884254

1-1

2-1

5-1

6-1

7-1

8-1

9-1

23818340

27881820

23781400

26381501

23981520

22848210

71533272

22615000

23618197

46066319

22082940

22082950

22848160

27881820

22282100

23781110

29015019

23818190

No. Code No.

Description

Metering Needle Assembly

"O" Ring (2pcs.)

Ball Link No.3

Retaining Screw

Dust Cover

Slide Valve

Carburetor Reducer 7mm (YELLOW)

"O" Ring

Needle Assembly

"O" Ring

Needle Holder Assembly

Fuel Inlet (No.15)

Throttle Stop Screw

"O" Ring

Carburetor Body (w/Thermo Insulator)

Thermo Insulator

Carburetor Rubber Gasket

Carburetor Sealing Washer

(5pcs.)

(3pcs.)

(71490000)

(71491000)

O.S. SPEED CARBURETOR REPAIR KIT 21

O.S. SPEED CARBURETOR

REPAIR PARTS SET 21

O.S. SPEED Carburetor Repair Parts Set 21

(71491000)

(73301612)

(73301812)

(22884254)

(73300305)

(72506100)

2.5mm x 1000mm

(22826145)

(21817010)

O.S. SPEED CILICONE TUBE

O.S. SPEED EXHAUST SEAL RING 21

(

10pcs.

)

O.S. SPEED PISTON PIN RETAINER 4mm (6pcs.)

O.S. SPEED DUST CAP SET FOR 12-30 CLASS

3mm(2pcs.) / 16mm(2pcs.) / 18mm(1pc.)

DUST CAP SET 3mm

DUST CAP SET 16mm

(3pcs.)

DUST CAP SET 18mm

3mm (2pcs.)/16mm (2pcs.)/18mm (1pc)

(71533255)
(71533260)
(71533265)
(71533270)

5.5

6.5

(71533280)
(71533085)
(71533290)

8.5

(71550001)

(71550002)

O.S. SPEED CLUTCH BEARING (1050ZZ 4pcs.)

O.S. SPEED CLUTCH BEARING (1050ZZ 10pcs.)

5-1

6-1

S.M3x3

1-1

2-1

8-1

9-1

C.M2.6x18

C.M3x18

7-1

C.M2.6x7

5-1

5-2

5-3

5-4