It is of vital importance, before attempting to
operate your engine, to read the general
'SAFETY INSTRUCTIONS AND WARNINGS'
section on pages 2-5 of this booklet and to strictly
adhere to the advice contained therein.
Also, please study the entire contents of this
•
instruction manual, so as to familiarize yourself
with the controls and other features of the
engine.
Keep these instructions in a safe place so that
•
you may readily refer to them whenever
necessary.
It is suggested that any instructions supplied
•
with the vehicle, radio control equipment, etc.,
are accessible for checking at the same time.
CONTENTS
SAFETY INSTRUCTIONS AND
WARNINGS ABOUT YOUR O.S. ENGINE
INTRODUCTION, BASIC ENGINE PARTS
INSTALLATION
AIR CLEANER
GLOWPLUG
TOOLS, ACCESSORIES, etc.
CARBURETOR CONTROLS
STARTING THE ENGINE &
RUNNING-IN('Breaking-in)
IF THE ENGINE FAILS TO START
ADJUSTMENT
2
~
~
11
8
11
~
12
12~13
13
14~15
16
~
17
16
CARBURETOR CLEANLINESS
5
BEFORE STARTING THE ENGINE
6
CARE AND MAINTENANCE
7
GUARANTEE
THREE VIEW DRAWING
EXPLODED VIEW
ENGINE PARTS LIST
CARBURETOR EXPLODED VIEW &
PARTS LIST
O.S. GENUINE PARTS &
ACCESSORIES
1
17
~
18
18~19
20
21
22
23
24
25
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
Remember that your engine is not a "toy", but a highly efficient internalcombustion machine whose power is capable of harming you, or others, if it is
misused.
As owner, you, alone, are responsible for the safe operation of your engine, so act
with discretion and care at all times.
If at some future date, your O.S. engine is acquired by another person, we would
respectfully request that these instructions are also passed on to its new owner.
The advice which follows applies basically to ALL MODEL ENGINES and is
grouped under two headings according to the degree of damage or danger
which might arise through misuse or neglect.
WARNINGS
These cover events which
might involve serious (in
extreme circumstances, even
fatal) injury.
NOTES
These cover the many other
possibilities, generally less obvious
sources of danger, but which, under
certain circumstances, may also
cause damage or injury.
2
WARNINGS
•
Model engine fuel is poisonous. Do not allow it to
come into contact with the
eyes or mouth. Always
store it in a clearly marked
container and out of the
reach of children.
Model engine fuel is also
•
highly flammable. Keep it
away from an open flame,
excessive heat, sources of
sparks, or anything else
which might ignite it. Do not
smoke or allow anyone else
to smoke, near to it.
•
Never operate your engine in an enclosed space. Model engines, like
automobile engines, exhaust deadly
carbon-monoxide. Run your engine
only in an open area.
Model engines generate
•
considerable heat. Do not
touch any part of your
engine until it has cooled.
Contact with the muffler
(silencer), cylinder head
or exhaust header pipe, in
particular, may result in a
serious burn.
3
This engine is intended for model cars.
•
Do not attempt to use it for any other
purpose.
Mount the engine in your model
•
securely, following the manufacturers'
recommendations, using appropriate
screws and locknuts.
Fit an effective silencer (muffler).
•
Frequent close exposure to a noisy
exhaust (especially in the case of the
more powerful highspeed engines)
may eventually impair your hearing
and such noise is also likely to cause
annoyance to others over a wide area.
NOTES
•
The wearing of safety glasses is also
strongly recommended.
Take care that the glowplug clip or
•
battery leads do not come into contact
with rotating parts. Also check that the
linkage to the throttle arm is secure.
For their safety, keep all onlookers
•
(especially small children) well back
(at least 20 feet or 6 meters) when
preparing your model for running.
4
•
To stop the engine, fully retard the
throttle stick and trim lever on the
trans-mitter, or, in an emergency, cut
off the fuel supply by pinching the fuel
delivery line from the tank.
•
Warning! Immediately after a glowplugignition engine has been run and is still
warm, conditions sometimes exist
whereby it is just possible for the engine
to abruptly restart if it is rotated over
compression WITHOUT the glowplug
battery being reconnected.
NOTES
5
The MAX-21RZ-V01b and MAX-21RZ-V01b(P) are
high performance 3.5cc class power units for oneeighth-scale radio-controlled 'off-road' or 'buggy' cars.
They have been designed to meet the exacting
requirements of the world's most expert drivers. An
exhaustive program of research, development and
prototype testing has resulted in one of the most
powerful production model racing car engines currently
available. The MAX-21RZ-V01b has a conventional
crankshaft, while the MAX-21RZ-V01b(P) employs a
special crankshaft with integral pilot shaft.
Standard accessories
Glow Plug A5
Exhaust Seal Ring Silicone Tubing
Dust Caps 3, 16, 18
NOTE: With this engine, the piston will feel tight at
the top of its stroke when the engine is cold. This
is normal. The piston and cylinder are designed to
achieve a perfect running clearance when they
reach their normal running temperatures.
Super Air Cleaner 201
NOTE
As delivered, the engine has its carburetor lightly
fit into its intake. Secure it changing its angle
according to the car chassis.
BASIC ENGINE PARTS
Heatsink Head
Carburetor
Type 21B
Crankshaft
SILICONE TUBING AND O-RINGS
Before installing the engine on the chassis:
Connect the intake chamber and the carburetor with
1.
the silicone tubing supplied.
(Note: In the event of the silicone tubing requiring replacement, use tubing of 2.5mm i.d. 5.5mm
o.d. and 85mm in length.)
2.Fit the exhaust seal ring supplied.
6
Crankcase
Mounting Lugs
Exhaust
Seal Ring
Silicone
Tubing
Intake
Chamber
INSTALLING THE GLOWPLUG
Fit washer to glowplug and
insert carefully into heatsink
head, making sure that it is
not cross-threaded
before tightening firmly.
Glow plug
Washer
ENGINE INSTALLATION
Make sure that the vehicle's engine mounting
surfaces are level and in the same plane. Poor
installation may cause distortion of the
crankcase, bearings, etc., resulting in erratic
running and loss of performance.
The recommended screws for securing the
engine are 3mm or 4-40 steel Allen hexagon
socket type.
If existing holes in the engine mount do not align
perfectly with engine mounting lugs, enlarge
them slightly with a needle-file so that screws are
in alignment with the mounting holes.
Chassis
Chamfer inside edges of bearers.
INSTALLATION OF THE CARBURETOR
As delivered, the engine has its carburetor lightly
fit into its intake boss. Secure it as follows.
Loosen the retainer screw, rotate the
1.
carburetor to its correct position and make
sure that it is pressed well down into the
intake boss, compressing the rubber gasket,
before retightening screw.
Rotate the retainer
2.
screw gently until it
stops, then tighten
a further 90-120˚.
Do not overtighten
the screw as this
will damage the
carburetor body.
7
Rotate the
retainer nut
gently until
it stops.
Tighten a
further
90-120˚
AIR CLEANER TYPE 201
This is a heavy-duty wet type air cleaner that has been developed specifically for 3.5cc 'off-road' model car
engines. It contains a specially impregnated filter element which more positively prevents highly damaging dust
and dirt from being drawn through the carburettor, yet allows engine performance to be maintained for longer
periods between element renewals. It is more compact than the standard O.S. HD Air Cleaner and this makes it
easier to install within a car body. This air cleaner is also supplied with a newly designed intake elbow that provides
more secure attachment to the caburetor.
Intake Elbow
Filter Element
End Plate
Assembly Screw
Center Tube
Element Base
Center Screen
8
Strap
Strap
ASSEMBLY
Slide the element base over the center tube (See
1.
Fig.1) and press down.
¡
If it is tight at the bottom, apply one or two drops of
fuel at the point marked in Fig.2
¡
Press down near to the center (not the outside) to
avoid risk of breaking the element base.
¡
Apply pressure until the element base fits firmly
against the collar of the center tube (Fig.3).
Element Base
Center Tube
Fig.1
2. Install the element.
¡
The element is already impregnated with a special
filter oil. As this oil is very sticky, take care, when
handling it, to prevent dust or dirt adhering to the
element, especially to its inner surface before
insertion of the center screen.
Press at center.
Apply one or two
drops of fuel.
Fig.2
Press down
firmly.
Fig.3
If your fingers become contaminated, wash them with
soap and water.
NOTE: During storage, the oil may have become
unevenly dispersed through the element. This will
be indicated if the blue color of the element
material appears patchy.
In this case, place the element in a small plastic
bag and gently rub the element between finger
and thumb to redistribute the oil.
¡
Now insert the cylindrical center screen into the
element, followed by the center tube.
Do not, at anytime, omit the screen: it is essential for
releasing air to the engine evenly.
¡
Attach the end plate, washer and retaining screw,
making sure that the element fits correctly between
the end plate and base.
Element
misaligned
9
INSTALLATION
Apply instant setting
1.
glue to the joint be-
Apply instant fixing glue.
Washer
tween the air cleaner
and the intake elbow
and secure with strap
supplied.
Fit the other end of
2.
Do not apply
glue to
carburettor
Assembly
Screw
Strut
the elbow over the carburettor intake and secure with
strap supplied. Do not use glue at this point.
It is advisable to brace the outer end of the air
3.
cleaner to the car chassis with a piano wire strut.
This will restrain the cleaner in the event of the
vehicle overturning or being involved in a collision.
REPLACEMENT OF ELEMENT
Under very dusty conditions, it is advisable to
1.
replace the filter element after each hour of running
time.
2.
Under less severe conditions, however, it may be
possible to operate for longer periods. The rate at
which the elements become unusable may be
determined as follows.
¡
After one hour of running time, remove the element
but, before discarding it, check the penetration of
foreign matter by cutting through the wall of the
element. If dirt has
penetrated 1/3rd or more from the
outer surface, each element must always be
replaced within one hour, when the vehicle is run
under similar conditions. If, on the other hand, the
element is much less deeply soiled, the engine may
be run a little longer before another new element is
installed, but remember to check the condition of the
discarded element, as before. If the old element is
examined in this way
every time a new element
is installed, one can more
closely estimate the safe
life of the element under
known running conditions.
¡
Remember that the condition of the filter element will
depend on weather, as well as track conditions. If, for
example, the element surface is still visible and
remains moist, further running is permissible.
¡
If, however, the surface is no longer visible, or if dust
adhering to the surface has become dry, it is time to
replace the element.
10
1
3
FURTHER PRECAUTIONS
When removing the air cleaner, check the inside of the
center tube and carburetor venturi. If any dirt is
detected, this indicates that the filter element was
incorrectly installed or should have been replaced
earlier.In this event, it is vitally important to wash out
the inside of the engine thoroughly, with alcohol or
fuel,before it is used again, otherwise rapid wear of
the piston, cylinder,bearings, connecting-rod, etc., will
occur. Obviously, it will be necessary to carry out the
same procedure with the air cleaner and to replace the
filter element.
NOTE: Be careful not to splash alcohol or fuel
over the filter element, or the filter oil will be
diluted, and the filter capacity lowered.
GLOWPLUG
Since the compatibility of glowplug and fuel may have
a marked effect on performance and reliability, it may
be worthwhile to choose the R/C type plug found
most suitable after tests.Recommended O.S. plugs
are A5 and No.8. Carefully install plug finger-tight,
before final tightening with the correct size plug
wrench.
The role of the glowplug
With a glowplug engine, ignition is initiated by the
application of a 1.5-volt power source. When the
battery 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
reduced load, allowing higher rpm, the plug becomes
hotter and, appropriately, fires the fuel/air charge
earlier; conversely, at reduced rpm, the plug become
cooler and ignition is retarded.
Glowplug life
Particularly in the case of very high performance engines,
glowplugs must be regarded as expendable items.
However, plug life can be extended and engine
performance maintained by careful use, i.e.:
Install a plug suitable for the engine.
•
Use fuel containing a moderate percentage of
•
nitromethane unless more is essential for racing
events.
Do not run the engine too lean and do not leave the
•
battery connected while adjusting the needle.
11
When to replace the glowplug
Apart from when actually burned out, a plug may
need to be replaced because it no longer delivers its
best performance, such as when:
Filament surface has roughened and turned white.
•
Filament coil has become distorted.
•
Foreign matter has adhered to filament or plug
•
body has corroded.
Engine tends to cut out when idling.
•
Starting qualities deteriorate.
•
TOOLS, ACCESSORIES, etc.
The following items are necessary for operating the
engine.
FUEL
Generally, it is suggested that the user selects a fuel
that is commercially available for model two-stroke
engines and contains 10-30% nitromethane. As a
starting point, we recommend a fuel containing 20%
nitromethane, changing to a fuel containing more nitro if
necessary. When the brand of fuel is changed, or the
nitro content increased, it is advisable to repeat the
running-in procedure referred to in the RUNNING-IN
paragraphs.
Please note that with high-nitro fuels, although power
may be increased for competition purposes, glowplug
elements do not last so long and engine life will be
shortened.
REMINDER!
Model engine fuel is poisonous. Do not
allow it to come into contact with the eyes
or mouth. Always store it in a clearly
marked container and out of the reach of
children.
Model engine fuel is also highly
flammable. Keep it away from open flame,
excessive heat, sources of sparks, or
anything else which might ignite it. Do not
smoke or allow anyone else to smoke,
near to it.
GLOWPLUG BATTERY
The power source for heating the glowplug may be
either a large, heavy-duty 1.5-volt cell, or a 2-volt rechargeable lead-acid cell with extended leads (or a
resistance) to reduce the applied voltage to approximately 1.5-v.
12
BATTERY LEADS
These are used to conduct current from the battery to
the glowplug. For convenience, special leads with a
suitable clip to fit the glowplug terminal, are
commercially available.
LONG SOCKET WRENCH
Recommended for easy removal and replacement of
the deeply recessed glowplug, the O.S. Long Socket
Wrench incorporates a special grip.
FUEL BOTTLE OR PUMP
For filling the fuel tank, a simple, polyethylene
"squeeze" bottle, with a suitable spout, is required.
Alternatively, one of the purpose-made manual or
electric fuel pumps may be used to transfer fuel
directly from your fuel container to the fuel tank.
SILICONE TUBING
This is required for the fuel line between the fuel tank
and engine.
ELECTRIC STARTER AND STARTER BATTERY
Use an electric starter with 12-volt battery for
starting the engine.
CARBURETOR CONTROLS
Three adjustable controls are provided on this
carburettor.
¡
The Needle-Valve:
For adjusting the mixture strength when the throttle
is fully open.
¡
The Mixture Control Screw:
For adjusting the mixture strength at part-throttle
and idling speeds, to obtain steady idling and
smooth acceleration to mid speeds.
¡
The Throttle Stop Screw:
For setting the minimum idling speed:
Ball Link
Slide Valve
Guide Screw
NOTE: Readjustment may be necessary,
occasionally to allow for changes in fuel formula
gear ratio or clutch engagement point.
13
Needle Valve
Mixture Control Valve
Assembly Screw
Throttle Stop Screw
STARTING THE ENGINE & RUNNING-IN ('Breaking-in')
For long life and high performance, every engine
needs to be 'run-in' or 'broken-in'. With care, runningin of the MAX-21RZ-V can be carried out with it
installed in the vehicle. Be sure to fit the air-cleaner to
the carburetor and to use a muffler-pressurized fuel
system.
The following procedure is suitable for these engines
when the O.S. T-2030 tuned silencer and a fuel
containing up to 30% nitromethane are used.
Use the same fuel as is to be employed for all initial
•
running and containing NOT LESS THAN 18%
lubricant.
Temporarily remove the glowplug to check that it
•
glows bright red when energized.
Open the Needle-Valve 3 turns from the fully closed
•
position.
Switch on the transmitter and receiver and set the
•
throttle very slightly opened from the idling position
(see sketch, top right).
DO NOT energize glowplug, but apply electric
•
starter to draw fuel to carburetor.
Now connect glowplug battery lead to heat the plug
•
filament and start the engine.
Needle Valve
Close
Open
14
0.3~0.5mm
Attention:
It is vitally important to set the throttle at the
correct position before starting the engine. If the
engine is allowed to run with the throttle too far
open under ''no load'' conditions (i.e. with the
driving wheels not in contact with the ground) it
will rapidly over-heat and may be seriously damaged.
When the engine starts, first allow it to operate in
•
short runs at the very rich starting settings, with the
glowplug battery still connected and the driving
wheels clear of the ground.
The rich mixture will, under these conditions,
provide adequate lubrication and cooling, indicated
by profuse smoke from the exhaust.
Next, disconnect the glowplug battery and try
•
running the car on the track. If the engine stalls,
open the throttle fractionally, but try to keep the
engine running as rich as possible: if it stops
because of being excessively over-rich, close
the Needle-Valve 30˚ and try again.
Run the car on the track until one tank of fuel has
•
been consumed, then close the Needle-Valve 30˚
and run the car for another full tank of fuel.
Repeat this procedure until 5 more tanks of fuel
have been consumed, during which time the throttle
may be opened for brief bursts of increased power.
If the engine stops at medium speeds, close the
Mixture Screw 45-90˚.
The position of the needle-valve
when starting the engine.
30˚
Needle
To stop the engine, close the throttle to idling
◆
speed, then shut it off completely with the trim lever
on the transmitter. To cut off the fuel supply, pinch
the fuel delivery line to the carburetor.
◆
If the engine should need to be disassembled (e.g.
for cleaning or minor parts replacement) it is
advisable to return the Needle-Valve to the original
rich, starting setting and check whether further
running-in time is required before the car is raced
again. In the event of any major working parts(e,g,
piston/cylinder liner assembly) being replaced, the
complete running-in should be repeated.
30˚
30˚
Close the needle-valve approx.
30˚ after running the vehicle for
one full tank of fuel.
Repeat this procedure several times.
15
IF THE ENGINE FAILS TO START
Check the following:
Glowplug battery discharged or glowplug defunct.
◆
◆
Fuel not reaching carburetor.
Engine flooded. Do not over-prime. (This could also
◆
cause hydraulic lock and damage the engine on
application of the electric starter.) Remove glowplug, close needle-valve and apply starter to pump
out surplus fuel.
FINAL ADJUSTMENT
◆
Run the vehicle (with throttle fully open) over the
longest available straight course, in order to observe
the model's speed. Next return the car to the starting
point, close the Needle-Valve 30˚ and repeat the run,
taking note of the improvement in performance.
Continue with further runs, gradually reducing the
Needle-Valve setting and aiming to achieve the
highest straight-line speed. Remember, however,
that, if the Needle-Valve is shut down too far, the
engine will overheat and, accompanied by visibly
diminished exhaust smoke, the model will lose
speed. At this point, throttle down immediately, stop
the vehicle and reopen the Needle-Valve 45~90˚.
◆
Having established the optimum Needle-Valve
setting, check the Mixture Control Valve setting as
follows.
◆
With the engine running, close the throttle and
allow it to 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, it is probable that
the idling mixture is too rich.
In this case, turn the Mixture Control Valve
clockwise 45~90˚. If, on the other hand, the engine
tends to speed up momentarily and then cut out
abruptly when the throttle is opened, the idling
mixture is too lean. Correct this by turning the
Mixture Control Valve counter-clockwise 45-90˚.
NOTE:
Mixture Control Valve adjustment should be
made in steps of not more than 45~90˚, carefully
checking the effect,on throttle response, of each
small adjustment.
Carry out adjustments patiently, under actual
◆
running conditions, until the engine responds
quickly and positively to the throttle control.
16
Warning!
Mixture adjustments (whether via the Mixture
Control Valve, or the Needle-Valve) cannot be
made accurately under 'no-load' conditions,
which, in any case, are not advised, since such
operation carries the risk of seriously damaging
the engine through over-revving and overheating.
◆
With the optimum mixture control position, light
smoke is visible during high speed running,and the
engine revolutions increase smoothly during
acceleration. 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
mixture control screw very slightly on the rich side of
the best rpm setting, as a safety measure.
◆
If the engine runs too fast with the throttle closed,
the throttle stop screw should be turned counterclockwise to allow the throttle opening to be
reduced.
Finally, beyond the nominal break-in period, a slight
◆
readjustment toward a leaner needle setting may be
required to maintain performance.
CARBURETOR CLEANLINESS
The correct functioning of the carburetor depends on
its small fuel orifices remaining clear.
(See Care and Maintenance section on Page19.)
BALL LINK AND SLIDE VALVE EXTENSION
■
When readjusting the position of the Ball Link, always
apply a 6mm spanner (wrench) to the flats in the
Slide Valve Extension, before attempting to loosen or
tighten the ball link retaining screw. Carefully ease
back the Dust Cover bellows to allow access to the
flats. If it should become necessary (e.g. for cleaning)
to disassemble the throttle parts, first unscrew the
Slide Valve guide screw and withdraw the complete
sub-assembly from the carburettor body. Use the
correct size (8mm) wrench when unscrewing the
Slide Valve from the Slide Valve Extension.
'Flats' for spanners
Slide Valve
17
Slide Valve Extension
REALIGNMENT OF MIXTURE CONTROL VALVE
■
In the course of making carburetor adjustments, it is
just possible that the Mixture Control Valve may be
inadvertently screwed in or out too far and thereby
moved beyond its effective adjustment range.Its basic
position can be found by first rotating the Mixture
Control Valve until its slotted head is flush with the
carburettor body. The valve is then screwed in exactly
1 turn to re-establish its neutral position.
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburetor body.
Then screw the valve in exactly
1 turn.
This is the standard position.
Mixture Control Valve
Carburetor Body
BEFORE STARTING THE ENGINE
Before starting the engine for the first run of the day,
1.
remove the glowplug and check the engine by
rotating the flywheel by hand. It should rotate
smoothly. Now turn the engine with an electric
starter until fuel is drawn into the carburetor. At first,
rotation may feel 'sticky' due to oily residue
remaining within the engine. The engine should
rotate freely after fresh fuel has been drawn into the
working parts.
Check the glowplug. If the plug element is distorted,
2.
off center, or has a white appearance, engine
performance may be below par. With racing type
engines, glowplugs have to be regarded as
expendable items. Therefore, replace the plug if
necessary.
3.Reinstall the glowplug and start the engine.
4.
When re-starting the engine, turn the flywheel by
hand, as before (but without removing the glowplug) to make sure that there is nothing unusual,
before energising the glowplug and applying the
starter.
18
Warning!
Do not attempt to turn the engine with the starter
if the engine is over-primed (flooded) with fuel.
To do so is likely to seriously damage the engine.
CARE AND MAINTENANCE
1.
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 outlet 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
2.
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
3.
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.
Then, inject some after-run oil into the engine, and
4.
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.
Finally, when cleaning the exterior of the engine,
5.
use methanol or kerosene. Do not use gasoline or
any solvent that might damage the silicone fuel
tubing.
Caution:
The rear crankshaft bearing of this engine uses a
special plastic retainer. If the front housing needs
to be heated to remove or replace the bearing, do
not allow the bearing to exceed 120˚C (248˚F),
otherwise it may be damaged and rendered
unserviceable.
19
GUARANTEE
This engine is constructed from the very best
materials available and to the very highest
engineering standards, using the most advanced
precision machinery. However, the extremely high
stresses imposed by car racing operation under very
severe conditions, stresses which are exacerbated by
the use of powerful fuels containing very high
concentrations of nitromethane, constitute hazards
which are beyond a manufacturer's control.
Accordingly, we regret that it is not possible to extend
our usual warranty terms to this particular engine -i.e.
no guarantee is offered against material wear, or
damage resulting therefrom, in actual use.
20
THREE VIEW DRAWING Dimensions(mm)
SPECIFICATIONS
Displacement
■
Bore
■
Stroke
■
Practical R.P.M.
■
Power output
■
Weight
■
3.46 cc(0.211cu.in.)
16.6 mm(0.654in.)
16.0 mm(0.630in.)
3,000
~
40,000 r.p.m.
2
.4 bhp / 30,000 r.p.m.
330g(11.6oz.)(01b)
333g(11.7oz.)(01b(P))
54
4-φ3.3
37
21
30.6
86
UNF1/4-28
15
)
45
22(29.4
21.6
44
101
101
29.5
13.4
( ) -01b(P)
21
EXPLODED VIEW
C.M2.6X15
e
1
2
22
1234567890
-=qwe
✽
Type of screw C…Cap Screw M…Oval Fillister-Head Screw
6
4
6
-1
7
C.M2.6X18
8
0
9
F…Flat Head Screw N…Round Head Screw S…Set Screw
4
3
5
w
-2
q
=
=
-
-A
C.M2.6X7
w
w
-2
-1
w
ENGINE PARTS LIST
Code No.
2 3704 060
1
2 3703 040
2
3
2 3906 000
2 3817 000
4
5
2 3705 000
2 3818 040
6
2 9015 019
6
-1
2 3818 190
7
8
2 3981 700
2 3731 000
9
2 3701 030
0
2 3730 000
-
23
2 3702 000
=
=
2 3702 020
-A
q
2 3714 000
2 3707 050
w
w
2 3707 060
-1
w
2 4025 923
-2
e
2 2447 005
7 1605 100
7 2411 000
7 2411 020
7 2411 050
7 2411 010
7 2411 040
7 2411 030
2 2826 140
The specifications are subject to alteration for improvement without notice.
Heatsink Head
Cylinder & Piston Assembly
Piston Pin
Piston Pin Retainer(2pcs.)
Connecting Rod
Carburetor Complete (Type 21B)
Carburetor Rubber Gasket
Carburetor Sealing Washer
Carburetor Retainer Assembly
Crankshaft Ball Bearing (Front)
Crankcase
Crankshaft Ball Bearing (Rear)
Crankshaft (for 21RZ-V01b)
Crankshaft (for 21RZ-V01b(P))
Gasket Set
Intake Chamber Assembly
Intake Chamber
Nipple No.2
Screw Set
Glow Plug A5
Super Air Cleaner 201(W/two filter elements)
201 Filter Elements (4pcs.)
Element Plate Set,Comprising:
Center Screen
Intake Elbow
Center Tube
Exhaust Seal Ring
Description
CARBURETOR EXPLODED VIEW
& PARTS LIST
3
-1
3
-2
2
3
-4
4
1
-1
1
-2
1
✽
Type of screw
C…Cap Screw M…Oval Fillister-Head Screw
F…Flat Head Screw N…Round Head Screw S…Set Screw
-
3
3
-3
6
5
7
8
9
C.M2.6X7
Code No.
1
2 3818 180
1
4 6066 319
-1
2 2781 800
1
-2
2
2 3818 500
2 3618 190
3
3
-1
2 3618 197
3
-2
4 6066 319
3
-3
2 3618 194
3
2 3818 176
-4
4
2 3818 120
5
0
4 5581 820
6
2 3818 251
7
2 3818 330
2 3818 220
8
9
2 2884 220
0
2 3818 400
-
2 9015 019
The specifications are subject to alteration for improvement
without notice.
Mixture Control Valve Assembly
Throttle Stop Screw
Needle Valve Assembly
Carburetor Body
Slide Valve Guide Screw
Slide Valve
Metering Needle Assembly
Slide Valve Extension
Dust Cover
Ball Link No.1
Carburetor Rubber Gasket
Description
"O"Ring(L) (2pcs.)
"O"Ring(S) (2pcs.)
Needle
"O"Ring for needle
Needle Holder Assembly
Universal Nipple No.9
24
RACING ENGINE PARTS
O.S. GENUINE PARTS & ACCESSORIES
■
GLOW PLUG No.8/A5
No.8
(
71608001
21RZ EXHAUST
■
HEADER PIPE
(
72101270
)
)
T-2030 TUNED SILENCER
■
(
72106030
A5
(
71605100
)
CRANKSHAFT
■■
CLAMP 1521
(
71530200
)
)
LONG SOCKET WRENCH
WITH PLUG GRIP
25
(
71521000
SUPER JOINT TUBE 21
■
)
(
72106300
■
)
DUST CAP SET
(
73300305
3
(
73300812
8
(
73301612
16
(
73301812
18
)
)
)
)
MEMO
26
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Copyright 2001 by O.S.Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan.
I
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&
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6-15 3-Chome Imagawa Higashisumiyoshi-ku
Osaka 546-0003, Japan
URL : http://www.os-engines.co.jp
TEL.(06)6702-0225
FAX. (06) 6704-2722
060100
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