O.S. engine MAX-25XZ User manual

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.
Expressly for 1/8 off-road truck (Truggy)
racing competitions
1
2-5
6
7
8
14
15
19-23
27-29
24-26
30-33
9
16
34-35
17
18
10-12
13
CONTENTS
INSTALLATION OF THE CARBURETOR
ENGINE INSTALLATION
STARTING THE ENGINE &RUNNING-IN
("Breakinh-in")
FINAL ADJUSTMENT
CARE AND MAINTENANCE,
CHECKING THE ENGINE
TROUBLE SHOOTING
ENGINE EXPLODED VIEW & PARTS LIST
CARBURETOR EXPLODED VIEW &
PARTS LIST
O.S. GENUINE PARTS & ACCESSORIES
THREE VIEW DRAWING
36-37
SAFETY INSTRUCTIONS AND
WARNINGS ABOUT YOUR O.S. ENGINE
ENGINE CONSTRUCTION
NOTES WHEN APPLYING AN ELECTRIC
STARTER
NOTES ON OPERATION
ABOUT THE ENGINE
BEFORE STARTING
BASIC ENGINE PARTS
CARBURETOR CONTROLS
GLOWPLUG
INSTALLATION OF THE STANDARD
ACCESSORIES
38-39
40

2
!
!

Remember that your engine is not a "toy", but a highly efficient internal-
combustion 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.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
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 NOTES
These cover events which
might involve serious (in
extreme circumstances, even
fatal) injury.
These cover the many other
possibilities, generally less obvious
sources of danger, but which, under
certain circumstances, may also
cause damage or injury.
3
!
WARNINGS
Model engine fuel is poi-
sonous. Do not allow it to
come into contact with the
eyesormouth.Alwaysstore
it in a clearly marked con-
tainer 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 en-
closed 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.
••
•
•

4
!

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.
Install 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.
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.
NOTES
•
•
•
•
•
•
5
!
NOTES
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 glowplug-
ignition 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.
•
Before starting the engine, always check
the tightness of all the screws and nuts
especially the mounting screws and
movable parts such as the throttle arm.
Missing retightening the loose screws
and nuts often causes the parts
breakage that is capable of harming you.

6
Piston
Cylinder Liner
Crankshaft
ENGINE CONSTRUCTION
With this engine, the piston will
feel tight at the top of its stroke
(TDC) when the engine is cold.
This is normal. The cylinder bore
has a slight taper. The piston
and cylinder are designed to
achieve a perfect running
clearance when they reach
operating temperature.
Near TDC
Slight taper
When the engine is cold. When the engine is hot.
7
NOTES WHEN APPLYING
AN ELECTRIC STARTER
Do not over-prime. This could
cause a hydraulic lock and damage
the engine on application of the
electric starter.
If over-primed, remove glowplug,
close needle-valve and apply
starter to pump out surplus fuel.
Cover the head with a rag to
prevent any pumped out fuel from
getting into your eyes.

8
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, as well as
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.
As delivered, the engine has the
carburetor lightly fit into its intake.
Secure it changing its angle according
to the car chassis.
NOTE
Please do not run on a public street, this
could cause serious accidents, personal
injuries and/or propetry damage.
Please do not run near pedestrians or
small children.
Please do not run in small or confined
areas.
Please do not run where loud noises can
disturb others, such as hospitals and
residential areas.
While Operating
NOTES ON OPERATION
9
Standard accessories
Glow Plug P3 T-type head (Turbo head)
1piece
Exhaust Seal Ring 1piece
Dust Cap 3, 16, 18 1piece each
The MAX-25XZ is a high performance .25
cu.in. class power unit for one-eight-scale
radio-controlled truck type (Truggy) cars.
It has been expressly designed for racing
competitions. It features a large size
outer head and T-type plug (turbo plug)
design.
The 21JN carburetor is supplied with
8mm reducers to manage different
course conditions.
(Hot Type)
ABOUT THE ENGINE

10
Tools, accessories, etc.The following items are
necessary for operating the engine.
T-2060 WN TUNED SILENCER ASSEMBLY
M2000 EXHAUST HEADER PIPE ASSEMBLY
T-2060SC WN TUNED SILENCER COMPLETE SET
SUPER AIR CLEANER 203 ASSEMBLY
BEFORE STARTING
Optional Extras
GLOW PLUG T-Type (Turbo Plug)
P3 is supplied with the engine. As
replacement, suggested O.S. plugs are
P3 and P4.
This is a heavy-duty wet type air cleaner
designed specifically for 3.5cc ‘off-road’ model
car engines.
This is designed to use with the T-2060
Tuned Silencer.
This is designed specifically for 3.5cc ‘off-road’
model car engines.
This is a set of T-2060SC Tuned Silencer and
M2000SC Exhaust Header Pipe Assembly.
T-2060SC WN TUNED SILENCER ASSEMBLY
M2000SC EXHAUST HEADER PIPE ASSEMBLY
This is designed to use with the T-2060SC
Tuned Silencer.
This is designed specifically for 3.5cc ‘off-road’
model car engines.
SUPER JOINT TUBE 21
28XZ HYPER FLYWHEEL SETS
They are designed to match the engine power
characteristics.
This is to use with joint tube connection type
silencer.
11
TOOLS
HEX SCREWDRIVER
SCREWDRIVER
Necessary for engine installation.
1.5mm, 2mm, 2.5mm
Necessary for carburetor adjustments.
No.1, No.2, etc
LONG SOCKET WRENCH WITH PLUG GRIP
Recommended for easy removal and
replacement of the angled and recessed
glowplug, the O.S.Long Socket Wrench
incorporates a special grip.
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 as long and
engine life will be shortened.
Items necessary for starting
!

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.
REMINDER!

12
FUEL FILTER
GLOWPLUG IGNITER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
To installed in the fuel line between
fuel tank and carburetor to prevent
foreign matter from entering the
carburetor.
FUEL PUMP
For filling the fuel tank, a simple,
polyethylene "squeeze" bottle,
with a suitable spout, is required.
STARTER BOX
For starting the engine.
SILICONE FUEL LINE
Heatproof silicone tubing of
approx. 5mm o.d. and 2mm i.d.
is required for the connection
between the fuel tank and
engine.
7.2V BATTERIES FOR STARTER BOX
Batteries for starter box.
Select according to the
starter box used. Be sure to
fully charge before using.
!

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.
13
Outer Head
Crankcase
Mounting Lugs
Exhaust
Cover Plate
Carburetor
Type 21JN
Crankshaft
BASIC ENGINE PARTS
Crankshaft Bearing (Front)

14
The Needle-Valve(Adjusted at the factory):
The Mixture Control Valve:
Four adjustable controls are provided on
this carburetor.
For adjusting the mixture strength when the
throttle is fully open.
For changing the mixture strength at mid
speed and acceleration. (Do not rotate the
screw more chan one turn.)
The Throttle Stop Screw
(Adjusted at the factory):
For setting the minimum idle speed:
For adjusting the mixture strength at part-
throttle and idle speed, to obtain steady
idling and smooth acceleration to mid speed.
The Metering Needle:
NOTE: Readjustment may be necessary,
occasionally to allow for changes in fuel
formula, gear ratio or clutch engagement
point.
CARBURETOR CONTROLS 21JN
Metering Needle
Throttle Stop
Screw
Mixture Control Valve
Needle Valve
Thermo Insulator
Carburetor Reducer
Ball Link
Dust Cover
15
GLOWPLUG
The role of the glowplug
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.
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.
Apart from when actually burned out, a plug may
need to be replaced because it no longer delivers its
best performance, such as when:
When to replace the glowplug
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.
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 P3 and P4.
Carefully install plug finger-tight, before
final tightening with the correct size plug
wrench.

16
Install the exhaust seal ring supplied.
Exhaust
Seal Ring
Glowplug
INSTALLATION OF THE DUST CAP SET
If the engine is to be stored or out of use for a
while, install the included exhaust and
carburetor dust caps to prevent foreign matter
from entering the engine.
Installing the glow plug. Insert P3 plug supplied
into heatsink-head carefully, making sure that
it is not cross-threaded before tightening firmly.
(All the O.S. T-Type plugs including the P3 are
not supplied with a washer.)
INSTALLATION OF THE STANDARD ACCESSORIES
17
INSTALLATION OF THE CARBURETOR
As delivered, the engine has its carburetor
lightly installed in the intake boss. Secure it
as follows.
Loosen the retainer screw, rotate the
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.
1.
2.
Rotate the retainer nut
gently until it stops.
Tighten further
120-180
Rotate the retainer screw gently until it
stops, then tighten a further 120-180 .
Do not overtighten the screw as this will
damage the carburetor body.
Note
Be careful not to damage the O rings when
removing the carburetor retainer from the
engine.
First, remove the retainer Retaining screw,
then pull out each part. Do not push the
part in or damage the O rings.
Retaining Screw
"O" Ring
"O" Ring
Pull out.
Pull out.

18
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.
Chamfer inside edges of bearers.
Do not allow bottom
of crankcase to
touch chassis.
Note:
Be sure to use a collet supplied when use a
optional 28XZ Hyper Flywheel Set.
The engine bottom may interfere with chassis
of some models. In this case, file off the
chassis so that the engine may not interfere
with the chassis when it is installed.
NOTE
19
STARTING THE ENGINE & RUNNING-IN ('Breaking-in)
PRESSURIZED FUEL SYSTEM
!

Before starting the engine, always
check the tightness of all the screws
and nuts especially the mounting
screws and movable parts such as
throttle arm. Missing retightening the
loose screws and nuts often causes
the parts breakage that is capable of
harming you.
Never run your vehicle without installing the air
cleaner. Dust and dirt that may otherwise be drawn
into the engine will rapidly shorten its life.
The somewhat violent changes of vehicle attitude
that occur in off-road running, combined with the
fact that, in buggy type cars, the fuel tank is often
located some distance from the carburetor, which
means that the fuel 'head' at the carburetor can vary
and upset running.Therefore,it is recommended that
a muffler pressurized fuel feed system be used.
Running- in is a procedure for an engine to come
close to actual running conditions (fuel, r.p.m.,
engine temperature, etc.).
Excessively rich running and prolonged low
speed running should be avoided. Prolonged low
speed running and low temperature running may
result in the oil in the fuel becoming gelled and
the piston/liner becoming stuck together.
RUNNING-IN ('Breaking-in)

20
The following procedure is suitable for this
engine when the O.S. T-2060WN tuned si-
lencer and a fuel containing up to 30% ni-
tromethane are used.
Fill the tank completely with fuel.
Temporarily remove the glowplug to check
that it glows bright red when energized.
Glow Plug Igniter
Pliers
Element glows when energized.
Replace the plug when the
element does not glow or is
burnt out.
Turn the needle-valve clockwise until it stops. This
is the fully closed position. Do not force it to turn
further.
Needle Valve
Open
Close
approx 0.5mm
The carburetor is set as shown below at the
factory. Start the engine as it is.
The needle-valve is set approx. 3.5 turns
opened from the fully closed position.
Throttle is set approx. 0.5mm open.
Approx. 0.5mm open factory setting with the
reducer removed
21
Metering needle and mixture control valve
are set at basic position. (Refer to P26.)
Turn the engine with starter box to draw fuel
into the engine.
Fuel
Deliver fuel into the carburetor.
Fuel tank side
Now connect glowplug battery lead to heat
the plug filament and start the engine.
Switch on the transmitter and make sure
that each linkage moves correctly.
approx 1mm
Set the throttle opening a little wider that the
factory setting by adjusting the Throttle Stop
Screw.
When the engines does not start or stops
right after being started, try the followings.
Set the needle-valve approx. 3 turns open
from the fully closed position. Do not force
the needlevalve to turn beyond a lightly
closed position.

22
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 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 approx. 2
liters 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˚.
Attention:
throttle trigger
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.
It is vitally important to set the
throttle at the correct position
before starting the engine.
When the engine starts, warm it up by
repeatedly increasing the rpm to medium
speed and back again to a fast idle with the
mixture set very rich, the glowplug
connected, and the driving wheels clear of
the ground. The rich mixture will provide
adequate lubrrication and cooling indicated
by profuse exhaust smoke.
23
The position of the needle-valve
when starting the engine.
Close the needle-valve approx.
30˚ after running the vehicle for
one full tank of fuel.
Repeat this procedure several
times.
Needle
30˚
Note:
In the event of any major working parts
(e.g. piston/cylinder liner assembly) being
replaced or the fuel being changed,
especially to high nitro fuel, the complete
running-in should be repeated.
Warning!
Do not touch rotating parts, engine and si-
lencer when stopping the engine as they
become very hot, and contact with them
may result in a serious burn.
To stop the engine, close the throttle to idle
speed and shut it off completely with the trim
lever on the transmitter then cut off the fuel
supply by pinching the fuel delivery tube to
the carburetor.
Fuel
How to stop the engine

24
FINAL ADJUSTMENT
Throttle Stop
Screw
Needle Valve
Metering Needle
Open Close Close
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, in order
to observe the model's speed. Next return
the car to the starting point, close the Needle-
Valve 15˚ 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, 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 45-90˚.
Final adjustment should be carried out only
after the running-in has been completed.
25
Warning!
Mixture adjustments (whether via the Metering
Needle, 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 rpm increases
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
metering needle slightly on the rich side of
the best rpm setting, as a safety measure.
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
idle mixture is too rich. In this case, turn the
Metering Needle 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 idle mixture is too
lean. Correct this by turning the Metering
Needle counter-clockwise 45-90˚.
NOTE:
Metering Needle 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.
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.

26
Finally, beyond the nominal break-in period,
a slight readjustment toward a leaner needle
setting may be required to maintain
maximum performance.
CARBURETOR CLEANLINESS
The correct functioning of the carburetor
depends on its small fuel orifices remaining
clear.
REALIGNMENT OF METERING NEEDLE AND
MIXTURE CONTROL VALVE
Mixture Control Valve
Carburetor Body
First rotate the Mixture Control
Valve until its slotted head is
flush with the carburetor body.
This is the standard position.
In the course of making carburetor
adjustments, it is just possible that the
Metering Needle and the Mixture Control
Valve may be inadvertently screwed in or out
too far and thereby moved beyond its
effective adjustment range. The basic
positions can be found by rotating the
Metering Needle until its slotted head is flush
with the ball link body.
Slide Valve
Carburetor Body
Metering Needle
Ball Link
Rotate the Metering Needle
until its slotted head is flush
with the ball link body.
This is the basic position.
27
CARE AND MAINTENANCE
1.
2.
3.
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.

28
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.
29
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.

30
Symptom
Cause Corrective action
Engine fails to fire.
Fuel tank is empty.
Fuel not reaching the engine.
Fill the tank with fuel and repeat
Priming procedure.
Glowplug element is burnt out.
Glowplug battery discharged
Replace glowplug.
Recharge or replace the battery.
Clogged fuel filter
Air cleaner and silencer inside is dirty.
Clean or replace fuel filter.
Replace cleaner element and clean inside silencer.
Over priming Remove glowplug and pump out excess fuel.
Fuel tubing is disconnected. Connect fuel tubing securely.
Fuel tubing is kinked, split or has a hole. Check the tubing carefully and replace if necessary.
Incorrect servo linkage Connect correctly after setting servo at neutral.
Reverse rotating direction of starter box. Mare sure it rotates counter clockwise seen
from crankshaft side.
TROUBLE SHOOTING
31
Symptom
Cause Corrective action
Engine fires intermittently but does not run.
Insufficient fuel in the tank. Fill the tank with fuel.
Deteriorated glowplug Replace glowplug.
Clogged fuel filter
Air cleaner and inside of silencer is dirty.
Clean or replace fuel filter.
Replace cleaner element and clean inside of silencer.
Engine overheated Wait until engine is cool.
Incorrect clutch release Adjust the tension of clutch spring.
Starting battery disconnected too soon. Do not disconnect plug battery and wait until
r.p.m. becomes stable.
Vibration causing air bubbles in fuel. Install "O" rings to the tank screws to
prevent bubbles.

32
Symptom
Cause Corrective action
Symptom
Cause Corrective action
Unstable idle
Unsuitable glowplug Use suggested glowplug in the instructions.
Unsuitable fuel
Do not use extremely high nitro or low oil content fuel.
Extremely light flywheel Add heavier flywheel.
Silencer is disconnected or is loose Install silencer securely.
Not reaching expected peak r.p.m.
Insufficient warming up or running-in. Set the needle only after warming up.
Complete running-in.
Silencer or manifold is not securely connected
or disconnected.
Replace seal ring.
Check the connections and secure them.
Fuel tubing from tank is split or broken. Replace the tubing.
33
Symptom
Cause Corrective action
Symptom
Cause Corrective action
Poor response
Deteriorated glowplug Replace glowplug.
Incorrect carburetor settings Readjust low r.p.m. range with metering
needle and mixture control valve.
Incorrect setting of transmitter Exponential function. Check the transmitter setting.
Poor r.p.m. drop
Throttle position open too far. Close metering needle to adequate position
to lower idle r.p.m.
Carburetor not fully seated Install carburetor securely.
Incorrect linkage Make sure the throttle servo linkage does not
bind and is connected correctly.
Metering needle closed too far. Open the metering meedle a little.

34
ENGINE EXPLODED VIEW
Type of screw
C…Cap Screw
＊
1
2
3
5
4
6
7
8
9
10
11
12
14
13
C.M2.6x7
C.M2.6x18
15
C.M3x18
9-1
3-1
35
ENGINE PARTS LIST
The specifications are subject to alteration for improvement without notice.
Outer Head Inner Head Gasket Set Cover Gasket Cylinder & Piston Assembly Piston Pin Piston Pin Retainer (2pcs.) Connecting Rod Carburetor Complete (Type 21JN) Carburetor Retainer Assembly "O" Ring (2pcs.) Crankshaft Ball Bearing (Front) Crankcase Crankshaft Ball Bearing (Rear) Crankshaft Cover Plate Screw Set Glow Plug T-P3 Exhaust Seal Ring Dust Cap Set ( 3mm,16mm,18mm)
Description
Code No.
No.
1 2 3
3-1
4 5 6 7 8 9
9-1
10 11 12 13 14 15
22854200 22854100 22854140 23764020 22853000 22856000 21817000 23755020 22848030 23981740 24881824 23731000 22851000 23730020 22852000 22857000 23763010 71641300 22826140 22884250

36
CARBURETOR EXPLODED VIEW
Type of screw
S...Set Screw
1
3
5
4
6
7
8
S.M3x3
1-1
2
9-2
3-1
5-1
9
10
11
12
6-1
7-1
9-1
8-1
37
The specifications are subject to alteration for improvement without notice.
CARBURETOR PARTS LIST

Ball Link No.3
Retaining Screw
Dust Cover
Metering Needle Assembly
"O" Ring (2pcs.)
Slide Valve
Carburetor Reducer 8mm (RED)
"O" Ring
Needle Assembly
"O" Ring
Needle Holder Assembly
Fuel Inlet (No.15)
Throttle Stop Screw
"O" Ring
Mixture Control Valve Assembly
"O" Ring (L) (2pcs.)
"O" Ring (S) (2pcs.)
Carburetor Body (w/Thermo Insulator)
Thermo Insulator
Carburetor Rubber Gasket
Description
Code No.
No.
1
1-1
2
3
3-1
4
5
5-1
6
6-1
7
7-1
8
8-1
9
9-1
9-2
10
11
12
23781400
26381501
23981520
23818340
27881820
22848210
71533000
22615000
23618197
46066319
22082940
22082950
22848160
27881820
23781600
46066319
22781800
22848130
23781110
29015019

38
(71641300)
P3
(72106300)
(71641400)
P4
(72106135)
(72106130)
(72106090)
(72106440)
(72101272)
(22826140)
(72106130)
(72106440)
(22826140)
(72106042)
O.S. GENUINE PARTS & ACCESSORIES
GLOWPLUG T-2060SC WN
TUNED SILENCER ASSEMBLY
Exhaust Seal Ring (2pcs.)
Joint Spring (3pcs.)
M2000SC EXHAUST
HEADER PIPE ASSEMBLY
Header Pipe Spring (2pcs.)
Exhaust Seal Ring (2pcs.)
T-2060SC WN TUNED
SILENCER COMPLETE SET
T-2060SC WN
Tuned Silencer Assembly
M2000SC
Exhaust Header Pipe Assembly
(72106430)
(72101272)
(22826140)
M2000 EXHAUST
HEADER PIPE ASSEMBLY
Header Pipe Spring (2pcs.)
Exhaust Seal Ring (2pcs.)
T-2060WN TUNED
SILENCER ASSEMBLY
SUPER JOINT TUBE21
39
(71812000)
(71812100)
(71801100)
(71813000)
(71813100)
(71801100)
(71521000)
(72413000)
(72413200)
LONG SOCKET WRENCH
WITH PLUG GRIP
DUST CAP SET
3mm (73300305)
8mm (73300812)
16mm (73301612)
18mm (73301812)
SUPER AIR CLEANER 203
203 Filter Element (4pcs.)
(5pcs.)
(3pcs.)
(3pcs.)
(3pcs.)
The specifications are subject to alteration for improvement without notice.
28XZ HYPER FLYWHEEL SET
(For MUGEN)
28XZ HYPER FLYWHEEL SET
(For KYOSHO)
28XZ Hyper Flywheel MUGEN
Collet
28XZ Hyper Flywheel KYOSHO
Collet
M2.6x7
(79871022)
M2.6x18
(79871055)
M3x18
(79871180)
CAP SCREW SET
(10pcs.)