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Copyright © 2014
321B Nitro Engine
Instruction Manual
INSTRUCTION MANUAL
It is important that before attempting to operate your engine that you read, understand and
strictly follow the outlined guidelines in the “Safety Instructions, Warnings and Notes” section
on pages 1-3 of this manual.
• Study the information provided in this manual in order to become familiar with the controls
and features of the engine.
• Keep these instructions in a safe place so that you may refer to them when needed.
• It is recommended that you keep the instructions for the vehicle, radio/transmitter
equipment, etc. accessible at the same time so that you may refer to them when needed.
Safety Instructions, Warnings & Notes
Engine Construction & Notes When Applying the Starter Box
About the Engine & Standard Included Accessories
Required Items & Basic Engine Parts
Carburetor Controls & Glow Plug
Installation of the Standard Accessories & Engine Installation
Starting & Breaking-In the Engine
Final Adjustment
Care & Maintenance
Troubleshooting
Engine Exploded View & Parts List
Carburetor Exploded View & Parts List
Engine Accessories
3D Drawing & Specications
CONTENTS
1-3
4-5
6-7
8-10
11-12
13-15
16-20
21-23
24-25
26-28
29-30
31-32
33
34
Model engine fuel is poisonous. Do not allow it to come into contact with the
eyes or mouth. Always store fuel in a clearly marked container and out of the
reach of children.
Model engine fuel is highly ammable. Keep it away from open ames,
excessive heat, sources of sparks, or anything else that could ignite it. Do
not smoke or allow anyone else to smoke near it.
Model engine exhaust, like automobile engine exhaust, contains deadly
carbon-monoxide. Never operate your engine in an enclosed space. Run
your engine only in an open, well ventilated area.
Model engines generate considerable heat. Do not touch any part of your
engine until it has cooled. Contact with the exhaust system or cylinder head
may result in a serious burn.
WARNINGS
01 34
Near TDC
Piston
Cylinder Liner
Near TDC
Near TDC
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
Carburetor Restrictor (Venturi)
SAFETY INSTRUCTIONS,
WARNINGS & NOTES
Remember, this engine is not a “toy”! This is an internal combustion engine that has the
potential to damage property, as well as harm you or others if misused. As the owner, you
alone are responsible for the safe operation of this engine. Act with discretion and care at all
times. If the ownership of this engine is transferred to another person, it is the responsibility
of the original owner to provide this manual to the new owner.
The following warnings apply to ALL MODEL ENGINES and are grouped under two
headings according to the degree of danger and/or damage which could occur due to
misuse or neglect of this product.
These cover events which could
cause serious, and in extreme
circumstances, even fatal injury.
These cover the many other and generally less
obvious sources of danger, but which under certain
circumstances may also cause damage or injury.
WARNINGS NOTES
3D DRAWING & SPECIFICATIONS
Displacement 3.46cc (0.211cu.in.)
Bore 16.6mm (0.654in.)
Stroke 16.0mm (0.630in.)
Practical R.P.M. 3,000 - 40,000 R.P.M.
Power Output 2.5ps / 34,000 R.P.M.
Weight 355g (12.52oz)
WARNING
33 02
• This engine is intended for use in model cars. Do not attempt to use it for any
other purpose.
• Mount the engine in your model securely. Always follow the manufacturer
recommendations, using the appropriate screws and locknuts.
• Install an effective throttle return device. This will close the carburetor in the event
that battery power is lost during operation.
• Install an effective silencer (tuned pipe). Frequent close exposure to a noisy
exhaust (especially in the case of more powerful high speed engines) may eventually
impair your hearing and such noise is also likely to cause annoyance to others.
• Eye protection is highly recommended.
• Ensure that the linkage to the throttle arm is secure.
• As a safety precaution, maintain a 20 foot (6 meters) distance between your model
and all bystanders (especially small children).
NOTES
Part Number Description
PTK-2542 P3 Turbo Glow Plug (Ultra Hot)
PTK-2060-1 PTK-2060 Tuned Pipe (No Manifold) (Welded Nipple)
PTK-2060 PTK-2060 Tuned Pipe w/Manifold (Welded Nipple)
PTK-2544 Off-Road Exhaust Manifold (for PTK-2060)
PTK-2090-1 PTK-2090 Tuned Pipe (No Manifold) (Welded Nipple)
PTK-2090 PTK-2090 Tuned Pipe w/Manifold (Welded Nipple)
PTK-2545 Off-Road Exhaust Manifold (for PTK-2090)
PTK-2516 6mm Aluminum Carburetor Restrictor
PTK-2518 6.5mm Aluminum Carburetor Restrictor
PTK-2519 7mm Aluminum Carburetor Restrictor
PTK-2520 7.5mm Aluminum Carburetor Restrictor
PTK-2521 8mm Aluminum Carburetor Restrictor
PTK-2522 6mm Aluminum "Elliptical" Carburetor Restrictor
PTK-2523 6.5mm Aluminum "Elliptical" Carburetor Restrictor
PTK-2524 7mm Aluminum "Elliptical" Carburetor Restrictor
PTK-2525 7.5mm Aluminum "Elliptical" Carburetor Restrictor
PTk-2526 8mm Aluminum "Elliptical" Carburetor Restrictor
ENGINE ACCESSORIES
* Specications are subject to change without notice.
WARNING: This product contains chemicals known to the State of California to
cause cancer, birth defects or other reproductive harm.
THIS PRODUCT IS NOT A TOY! NOT FOR CHILDREN UNDER 14 YEARS.
For proper opertation and to avoid risk of damage and injury, read and follow all
instructions before operating this product. Failure to comply may result in excessive
heat, re, property damage and serious injury.
NOTES
03 32
• Before starting the engine, verify that all fasteners, especially those at joints and
moving parts (such as the throttle arm) are tight and secure. Loose fasteners are
often the source of catastrophic problems and could lead to injury or property
damage.
• To stop the engine during normal operation, reduce the throttle to neutral, ip the
car over and push a blunt rubber object against the ywheel.
• To stop the engine in the event of an emergency, use a blunt rubber object to
plug the exhaust and ood the engine (recommended), or cut off the fuel supply by
pinching the fuel delivery line from the fuel tank. In the event of an emergency DO
NOT attempt to stop the engine at the ywheel.
• WARNING! Immediately after a glow type engine has been shut off, while the
engine is still warm, conditions exist that make it possible for the engine to abruptly
re-start if the piston is rotated through the compression point (top dead center:
TDC), WITHOUT the glow plug igniter being connected.
No. Part Number Description
1 PTK-2529 Ball Link
1-1 PTK-H-4000 3x3mm Set Screw
2 PTK-2535 Carburetor Boot
3 PTK-2530 Low Speed Needle
3-1 PTK-2531 Low Speed Needle O-Ring
4 PTK-2503 Slide Valve (Carburetor Complete)
5 PTK-2524 Carburetor Restrictor – 7mm “Elliptical”
5 PTK-2526 Carburetor Restrictor – 8mm “Elliptical”
5-1 PTK-2517 Carburetor Restrictor O-Ring
6 PTK-2540 High Speed Needle
6-1 PTK-2541 High Speed Needle O-Ring
7 PTK-2537 High Speed Needle Housing
7-1 PTK-2538 Fuel Inlet with Gasket
8 PTK-2543 Idle Screw
8-1 PTK-2536 Idle Screw O-Ring
9 PTK-2532 Mid Rangle Needle
9-1 PTK-2533 Mid Range Needle O-Ring Large (2)
9-2 PTK-2534 Mid Range Needle O-Ring Small (2)
10 PTK-2513 Carburetor Outer O-Ring
* Specications are subject to change without notice.
31 04
ENGINE CONSTRUCTION
This engine uses a chrome plated brass sleeve with a tapered cylinder wall. When the engine
is cold, the piston will feel tight when rotated through the top of its stroke, or Top Dead
Center (TDC). This is normal. The cylinder will expand and will achieve correct clearance once
normal operating temperature has been reached.
NOTE: When this engine is new, DO NOT try to turn the crankshaft and rotate the piston
through TDC, as this will jam the piston in the cylinder.
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Carburetor Restrictor (Venturi)
Slide Boot
O-Ring
12
8
9
10
11
M2.6x18
M2.6x7
4
1
3
2
5
6
7
M3x18
1
3
5
6
7
8
S.M3x3
1-1
2
9-2
3-1
5-1
9
10
6-1
7-1
9-1
8-1
Dimensions (mm)
13
CARBURETOR EXPLODED VIEW
4
05 30
NOTES WHEN APPLYING
THE STARTER BOX
DO NOT over prime the engine. This could cause a hydraulic lock and damage the engine
when the starter is applied.
• If over-primed, remove the glow plug, close the high speed needle valve, cover the head
with a rag and apply the starter to pump out excess fuel. The rag will help to prevent fuel
from coming into contact with your eyes.
Idle Screw
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Carburetor Restrictor (Venturi)
Slide Boot
No. Part
Number
Description
1 PTK-2501 Cooling Head
2 PTK-2508 Turbo Plug Button Head
3 PTK-2509 0.1mm & 0.2mm Head Gasket/Shim Set
4 PTK-2507 Complete Piston/Sleeve/Rod Assembly
5 PTK-2503 Complete Carburetor
6 PTK-2514 Carburetor Retainer Assembly
7 PTK-2504 7x19x6mm Front Engine Bearing
8 PTK-2502 Crankcase
9 PTK-2505 14x25.4x6mm Ceramic Rear Bearing
10 PTK-2506 Crankshaft
11 PTK-2512 Rear Cover Plate O-Ring
12 PTK-2511 Rear Cover Plate
13 PTK-2542 P3 Turbo Glow Plug (Ultra Hot)
* Specications are subject to change without notice.
* See additional option parts on Pg.33
29 06
ABOUT THE ENGINE
The ProTek R/C Samurai 321B is a 3.5cc high performance short-stroke nitro engine
produced and assembled in Japan by one of the most highly respected model engine
manufacturers in the industry. Designed for off-road radio-controlled competition racing, the
engine is ideal for 1/8 Scale Buggy and Truggy use while featuring a turbo glow plug and
slide carburetor. With its easy-to-tune and consistently stable operating characteristics, the
Samurai 321B is the ideal engine of choice for the racer seeking a reliable engine with a
smooth power band and great runtime.
NOTE: The carburetor is only lightly t into the engine and is not fully installed. This
allows the user to adjust the angle and make necessary adjustments to suit their
specic application.
12
8
9
10
11
M2.6x18
M2.6x7
4
1
3
2
5
6
7
M3x18
Dimensions (mm)
13
ENGINE EXPLODED VIEW
Part Number Size Pieces Used in an Engine
PTK-2515 2.6x7mm Rear Cover Plate Screw - 4
PTK-2514 2.6x18mm Carburetor Retainer Screw (Complete) - 1
PTK-H-1208 3x18mm Cooling Head Retaining Screw - 4
07 28
STANDARD INCLUDED
ACCESSORIES
• ProTek P3 - Ultra Hot Turbo Glow Plug (PTK-2542) (1)
• 0.1mm Cylinder Head Shim (PTK-2509) (1)
• High Temp Exhaust Gasket (PTK-2528) (1)
• 7mm “Elliptical” Carburetor Restrictor (PTK-2524) (1)
8mm “Elliptical” Carburetor Restrictor (PTK-2526) (1)
• 3mm, 16mm & 17mm Dust Cap (PTK-2527) (1)
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
High Speed
Needle
(Needle Valve)
7
8
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
O-Ring
7
8
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
O-Ring
8
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
High Speed
Needle
(Needle Valve)
7
8
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
7
8
TROUBLESHOOTING
SYMPTOM: NOT REACHING PEAK RPM
Cause Corrective Action
Insufcient warming up or break-in. Set the needles only after warming up.
Complete the break-in process.
Silencer or manifold are not securely
connected or are disconnected.
Replace gasket.
Check and secure the system.
Fuel tubing from tank is split or broken. Replace the tubing.
Cause Corrective Action
Deteriorated glow plug. Replace glow plug.
Incorrect carburetor settings. Readjust low RPM range with Low Speed
Needle and Mid Needle.
Incorrect Setting of transmitter Exponential
function.
Check the transmitter setting.
Incorrect Linkage. Make sure the throttle servo linkage does
not bind and is connected correctly.
SYMPTOM: POOR THROTTLE RESPONSE
Cause Corrective Action
Throttle position open too far. Close Low Speed Needle to adequate
position to lower idle RPM.
Carburetor not fully seated. Install carburetor securely.
Low Speed Needle closed too far. Open the Low Speed Needle a little.
SYMPTOM: POOR RPM DROP
REQUIRED ITEMS &
BASIC ENGINE PARTS
The following items are required to operate the engine.
FUEL
The user should only use high quality fuel for two stroke glow type
engines that contains 10-30% nitromethane. Fuel with 20% nitro
content is recommended for break in. Then, change to a fuel with a
higher nitro content later if desired. When the brand of fuel is changed,
or the nitro content is increased, it is advisable to repeat a short break
in procedure referred to in the BREAKING IN section. Please note that
high nitro content fuels produce more power at the expense of reduced
engine life. This will also shorten the life of the glow plug element.
WARNING
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. Wash hands after use.
Model engine fuel is highly ammable. Keep away from open ames,
excessive heat, sparks, or anything else that could ignite it. Do not smoke
or allow anyone else to smoke near it.
FUEL FILTER
Install the lter in the fuel line between the fuel tank and the
carburetor to prevent dust from entering the carburetor.
GLOW PLUG IGNITER
Commercially available, a glow plug igniter is a handy tool
that uses an integrated battery to heat the glow plug.
Recommended: PTK-7605 - ProTek R/C “SureStart” Rechargeable
Glow Ignitor w/Charger (2100mAh NiMH)
STARTER BOX
Used to start the engine.
Recommended: PTK-4500 - ProTek R/C SureStart 1/8 Off-Road
Starter Box
27 08
Near TDC
Piston
Cylinder Liner
Near TDC
Carburetor Restrictor (Venturi)
Idle Screw
Mid Needle
High Speed
Needle
(Needle Valve)
Carburetor Restrictor (Venturi)
Slide Boot
Cause Corrective Action
Insufcient fuel in the tank. Fill the tank with fuel.
Deteriorated glow plug. Replace glow plug.
Clogged fuel lter.
Air cleaner or internal silencer are dirty.
Clean or replace fuel lter.
Replace air cleaner element and clean
inside silencer.
Engine is over heated. Wait until engine is cool.
Incorrect clutch release. Adjust the tension of the clutch spring.
Glow plug battery disconnected too soon. Wait until RPM becomes stable before
disconnecting plug battery.
Vibration causing air bubbles in fuel. Install o-rings to the fuel tank screws to
prevent bubbles.
TROUBLESHOOTING
SYMPTOM: ENGINE FIRES INTERMITTENTLY
BUT DOES NOT RUN
Cause Corrective Action
Incorrect glow plug. Use the glow plug recommended in the
instructions.
Unsuitable fuel. Do not use extremely high nitro or low oil
content fuel.
Extremely light ywheel. Add heavier ywheel.
Silencer or manifold are not securely
connected or are disconnected.
Replace seal ring.
Check and secure the system.
SYMPTOM: UNSTABLE IDLE
09 26
STARTER BOX BATTERIES
Use the battery type that is recommended by the starter box
manufacturer. Ensure that the battery is fully charged before use.
Recommended: ECP-LPH-5000-2S30 (x2) - EcoPower 2S Li-Poly
Battery Pack
FUEL BOTTLE
Use this to ll the fuel tank.
Recommended: PTK-7600 - ProTek R/C “Fast Fill” Fuel Bottle (500cc)
& PTK-7603 - ProTek R/C “Quick Pit” Fuel Gun
SILICONE FUEL LINE
Heatproof silicone tubing suitable for nitro fuel with an approximate
5mm outer diameter and 2mm inner diameter is required to make the
connection between the fuel tank and the engine.
TOOLS
HEX SCREWDRIVER
Use for engine installation. 1.5mm, 2mm, 2.5mm, 3mm
Recommended: PTK-8227 - ProTek R/C “TruTorque”
Metric Hex Driver Set
SCREWDRIVER
Necessary for carburetor adjustments. No.1, No.2, etc.
Recommended: PTK-8219 - ProTek R/C “TruTorque” Flat
Blade Screwdriver (4mm)
LONG SOCKET WRENCH
WITH PLUG GRIP
Recommended for easy removal and replacement of the glow
plug, this socket wrench incorporates a special internal grip.
Recommended: PTK-8202 - ProTek R/C “TruTorque” 4-in-1
Multi-Wrench
ProTek R/C offers a full line of batteries, chargers, servos and
accessories. Visit www.ProTekRC.com for more information.
Cause Corrective Action
Fuel tank is empty.
Fuel not reaching the engine.
Fill the tank with fuel and repeat priming
procedure.
Glow plug element is burned out.
Glow plug battery discharged.
Replace glow plug.
Recharge or replace the battery.
Clogged fuel lter.
Air cleaner or internal silencer are dirty.
Clean or replace fuel lter.
Replace air cleaner element and clean
inside silencer.
Engine is over primed (ooded). Remove glow plug and pump out excess
fuel.
Fuel tubing is disconnected.
Fuel tubing is kinked, split or has a hole.
Connect fuel tubing securely.
Check the tubing carefully and replace if
necessary.
Incorrect servo linkage. Connect correctly after setting servo at
neutral.
Reverse rotating direction of the
starter box.
Make sure the starter box rotates counter
clockwise as seen from crankshaft side.
TROUBLESHOOTING
SYMPTOM: ENGINE FAILS TO START
25 10
BASIC ENGINE PARTS
Cooling Head
Exhaust
Back Plate
Mounting Lugs
Crankcase
Front Bearing
Crankshaft
Carburetor
INSTALLING DUST CAPS
When storing the engine install the cap on the exhaust port, carburetor, etc. to prevent dust
from entering the engine. This can cause permanent damage.
CHECKING THE ENGINE
As the engine wears, performance will decrease. It is suggested to replace parts as needed
when the following symptoms are detected.
• Engine sound changes and easily overheats.
• Power has dropped.
• Idling is unstable and/or engine cuts out when idling.
In most cases, the bearings, piston & sleeve assembly, connecting rod and/or crankcase
have become worn. Check the parts carefully and replace as needed.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Dirt and dust may lodge in marked places
11 24
CARBURETOR CONTROLS
The following procedure is recommended for this engine when the ProTek R/C P3,
PTK-2060 or PTK-2090 tuned pipe and fuel containing up to 30% nitromethane are used.
HIGH SPEED NEEDLE (NEEDLE VALVE)
Use to adjust the fuel mixture when the throttle is fully open. (*3½ Turns from fully closed)
MID NEEDLE (MIXTURE CONTROL VALVE)
For changing the fuel mixture at mid speed and acceleration. DO NOT rotate the screw more
than one turn. (*2¾ turns from fully closed)
LOW SPEED NEEDLE (METERING NEEDLE)
For adjusting the fuel mixture at partial throttle and idle speed to obtain steady idling and
smooth acceleration to mid speed. (*5½ turns from fully closed)
IDLE SCREW (THROTTLE STOP SCREW)
For setting the minimum idle speed. This is adjusted at the factory.
NOTE: We recommend
you double check
the needle settings
prior to beginning the
break in process. The
settings are set at
the factory, but slight
readjustment may be
necessary to allow
for changes in fuel
formula, gear ratio or
clutch engagement
point.
*Factory default settings.
When screwing the needles all
the way in, the slide must be in
the fully open position.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
CARE & MAINTENANCE
1 The small particles of foreign matter that may be present in any fuel may obstruct fuel
ow, causing erratic engine performance, unreliable operation or permanent damage to
the engine. It is recommended that a high quality in-line fuel lter be installed between the
fuel tank and carburetor.
2 Do not forget to clean or replace lters regularly to remove the dirt and other material that
can accumulate. Additionally, the carburetor may require occasional maintenance.
3 At the end of each operating session, drain out any remaining fuel from the fuel tank.
Then restart the engine to burn off any fuel that may remain inside the engine. Repeat
this procedure until the engine fails to start. This should be performed while the engine
is still warm.
4 Remove the glow plug and inject a small amount of after-run oil into the engine from the
glow plug hole in the combustion chamber. Then turn over the engine with the starter box
for 4 to 5 seconds to distribute the oil to the working parts inside the engine.
NOTE: Do not inject after run oil in through the carburetor, as this may cause the
carburetor o-rings to deteriorate. These procedures will reduce the risk of starting
difculties or corrosion after a period of storage.
5 Finally, when cleaning the exterior of the engine, use an approved nitro cleaner. Do not use
gasoline, kerosene, or any petroleum based chemical as this could damage engine seals
and other components.
NOTE: This engine uses a silicone ramped crankshaft. DO NOT use light oil, waterdisplacing oil, kerosene, or other petroleum based oils as an after run oil or to clean the
crank, as this will permanently damage the silicone. Use alcohol or nitro fuel to clean
the crank.
23 12
GLOW PLUG
Since the chosen glow plug and fuel type will effect performance and reliability, it will
be worthwhile to test with different plugs to nd the best plug for your application. We
recommend the ProTek R/C P3 plug. Carefully install the plug nger tight before nal
tightening with the correct size plug wrench.
THE ROLE OF THE GLOW PLUG
With a glow plug engine, ignition is initiated when a 1.5 volt power source is connected to
the plug. When the engine is running and the power is disconnected, the heat retained within
the combustion chamber remains sufcient to keep the plug lament glowing. This keeps the
engine running. Ignition timing is automatic. This means under reduced load and higher RPM,
the plug gets hotter and res the fuel/air charge earlier in the piston stroke; at reduced RPM
the plug becomes cooler and ignition is retarded ring the charge later in the stroke.
GLOW PLUG LIFE
In the case of high performance nitro engines, glow plugs must be regarded as expendable
items. However, plug life can be extended and engine performance maintained by careful
use, i.e.:
• Use 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 igniter battery connected while making
needle adjustments.
WHEN TO REPLACE THE GLOW PLUG
Apart from when actually burnt out, a plug may need to be replaced because it no longer
delivers its best performance, such as when:
• Filament surface is rough and has turned white.
• Filament coil has become distorted.
• Foreign matter has adhered to lament or plug body has corroded.
• Engine tends to cut out when idling.
• Engine becomes more difcult to start.
• After the break in period, a leaner needle setting may be required to maintain maximum
performance.
CARBURETOR CLEANLINESS
The small fuel orices must be kept clear to ensure correct carburetor function.
• REALIGNMENT OF THE LOW SPEED NEEDLE & MID NEEDLE
When making carburetor adjustments, it is possible that the low speed needle and mid
needle may be inadvertently screwed in or out too far and thereby moved beyond the
effective adjustment range. The basic positions can be found by rotating the low speed
needle until its slotted head is ush with the ball link body.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Mid Needle
Carburetor Body
Slide Valve
Carburetor Body
Low Speed Needle
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
First rotate the mid needle until its slotted
head is ush with the carburetor body. This is the
standard position.
5.5 turns out. Make adjustments with the slide in the open position.
2¾ turns out. Make adjustments with the slide in the open position!
13 22
INSTALLATION OF THE
STANDARD ACCESSORIES
INSTALL THE GLOW PLUG
Insert the included plug into the heatsink head carefully making sure that it is not cross
threaded before tightening rmly.
INSTALL THE INCLUDED EXHAUST GASKET.
One 0.1mm cylinder head shim and one 0.2mm head shim are installed in the engine when it
leaves the factory. An additional 0.1mm head shim is supplied with the engine. You may add
it for break in, when you are trying to achieve increased run time at the expense of a loss in
power, or if the glow plug tends to burn out due to high temperature and/or high humidity.
INSTALLING THE CARBURETOR REDUCER
Choose the reducer according to the track conditions.
• 7mm Installed from the factory.
• 8mm Included in package.
INSTALLATION OF THE DUST CAP SET
If the engine is going to be stored, install the included exhaust and carburetor dust caps to
prevent debris or other foreign matter from getting inside the engine.
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Exhaust
Gasket
Glowplug
Retaining Screw
O-Ring
O-Ring
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Dirt and dust may lodge in marked places
7
8
• With the engine running, close the throttle and allow it to idle for about ve seconds
and then open the throttle to the full throttle position. If, at this point, the engine puffs out
excessive smoke and the vehicle does not accelerate smoothly and rapidly, it is likely that
the idle mixture is too rich. In this case, turn the low speed needle clockwise 45-90°. If the
engine speeds up momentarily and then cuts out abruptly when the throttle is opened, the
idle mixture is too lean. Correct this by turning the low speed needle counter clockwise 45-90°.
NOTE: Low speed needle adjustments should be made in increments no more than
45-90°, carefully checking the effect on throttle response with each small adjustment.
• Carry out adjustments patiently under actual running conditions, until the engine responds
quickly and positively to the throttle inputs.
WARNING!
Mixture adjustments (whether via the low speed needle, or the high speed needle),
cannot be made accurately under ‘no load’ conditions. These adjustments are not
recommended and carry’s 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 steadily during acceleration. Remember, if the engine is
operated with a lean fuel/air mixture, it will overheat and run unevenly. It is advisable to set
both the high speed needle and low speed needle 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 idle screw should be
turned counter-clockwise to reduce the throttle opening.
21 14
INSTALLATION OF
THE CARBURETOR
The carburetor is only lightly installed into the intake boss when it leaves the factory. Follow
the steps below to complete the installation.
1 Loosen the retainer screw, rotate the carburetor into the position that best suits your
application and make sure that it is fully seated into the intake boss, compressing the
rubber gasket.
2 Gently turn the retainer screw until it stops, then tighten it an additional 120° - 180°. Do
not over tighten 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. Do not push the part in or it could damage the o-rings.
Piston
Near TDC
When the engine is hot.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
Dirt and dust may lodge in marked places
Low Speed Needle
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
FINAL ADJUSTMENT
• Final adjustment should be performed only after the break-in has been completed.
• Run the vehicle down the longest straight away at full throttle to observe the speed. Bring
the car back to the starting point, close the high speed needle 30° and repeat the run,
taking note of the improvement in performance.
• Continue with additional runs, gradually reducing the high speed needle setting with a goal
to achieve the highest straight line speed. Remember that if the high speed needle is shut
too far the engine will run lean and overheat, accompanied by visibly diminished exhaust
smoke. At this point the model will begin to lose speed. If this happens, throttle down
immediately, stop the vehicle and open the high speed needle 45-90°.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
High Speed
Needle
Idle Screw
High Speed Needle
Low Speed Needle
Open
Close
Close
Open
HIGH SPEED NEEDLE
LOW SPEED NEEDLE
More fuel
Less fuel
More fuel Less fuel
Mid Needle
Carburetor Body
Slide Valve
Carburetor Body
Low Speed Needle
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
First rotate the mid needle until its slotted
head is ush with the carburetor body. This is the
standard position.
5.5 turns out. Make adjustments with the slide in the open position.
2¾ turns out. Make adjustments with the slide in the open position!
Dirt and dust may lodge in marked places
15 20
ENGINE INSTALLATION
Make sure that the vehicles engine mount surfaces are level, and on the same plane.
Poor installation may cause distortion of the crankcase, bearings, etc, resulting in erratic
performance and permanent damage.
The recommended screws for securing the engine are Allen head, hexagon socket type 3mm
or 4-40 steel screws.
If existing holes in the engine mount do not align perfectly with the engine mounting lugs in
the crankcase, enlarge the holes in the lugs slightly with a needle le so that the screws are
perfectly aligned with the engine mount holes.
• Do not allow the bottom of the crankcase to touch the chassis.
• If needed, chamfer the inside edges of the engine mounts for clearance.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
NOTE: In the event that you replace any of the major engine components (piston,
sleeve, con rod, crankshaft or bearings), a brief break-in should be performed. If you
change to a fuel with higher nitro content, the engine will need to be re-tuned.
HOW TO STOP THE ENGINE
To stop the engine during normal operation, reduce the throttle to neutral, ip the car over
and push a blunt rubber object against the ywheel. DO NOT use your ngers!
WARNING!
Do not touch rotating parts, the engine, or the tuned pipe; these components get
extremely hot and contact with them may result in a serious burn or other injury.
Piston
Near TDC
When the engine is hot.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Pliers
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Approx. 0.5mm open
factory setting with the
restrictor removed.
approx 1mm
High speed needle position when
starting the engine.
Needle
30º
Close the high speed
needle approximately
30° as needed. This
procedure will be repeated
several times throughout
the break-in process.
Idle Screw
High Speed Needle
Low Speed Needle
Open
Close
Close
Open
HIGH SPEED NEEDLE
LOW SPEED NEEDLE
Mid Needle
Slide Valve
Carburetor Body
Low Speed Needle
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
First rotate the mid needle until its slotted
head is ush with the carburetor body. This is the
standard position.
5.5 turns out. Make adjustments with the slide in the open position.
Dirt and dust may lodge in marked places
19 16
STARTING & BREAKING-IN
THE ENGINE
WHILE OPERATING
• DO NOT drive the model on a public street! This can cause serious accidents, personal
injuries and/or property damage.
• DO NOT operate near pedestrians or small children.
• DO NOT operate in small or conned areas.
• DO NOT operate in areas where loud noises can disturb others, such as residential areas.
WARNING
Before starting the engine, make sure all fasteners are tight, especially those at joints and
moving parts, such as the throttle arm. Loose fasteners are often the source of damaged
components and could lead to injury and/or property damage.
BREAKING-IN
The break-in procedure is performed to prepare the engine for running conditions (fuel,
RPM, engine temperature, etc). Excessively rich and prolonged low speed running should be
avoided. Running at low speeds and low temperatures for prolonged periods of time will have
a negative effect on the performance and lifespan of your engine.
PRESSURIZED FUEL SYSTEM
• The constant changes in vehicle attitude that occur in off-road conditions, combined
with the distance between the fuel tank and carburetor can negatively affect performance.
Because of this, it is recommended that only a mufer with a pressurized fuel feed system
be used.
• Never run your vehicle without installing the air lter. The dust and dirt that will be drawn
into the engine will cause permanent damage to the components.
NOTE: It is incredibly important to set the throttle to the neutral
position before starting the engine. If the engine is allowed to run
with the throttle open too far under “no load” conditions (i.e. with
the driving wheels not in contact with the ground), the engine may
overheat and could be damaged.
HEAT CYCLE BREAK-IN METHOD
The purpose of this break in method is to heat cycle the engine without subjecting the
components to the stress that comes from breaking-in an engine that is overly rich and cold.
You want the engine to reach temperatures in the low 200°F (9 3ºC) range to reduce stress
on the components.
Pre-heat the engine to approximately 150°-160°F (66º-71°C) using an engine heater or heat
gun before starting for the rst time and pre-heat the engine each time you start it during the
break-in process. Additionally, if you have trouble keeping the temperature in the 200°F range
while the engine is running, it may be benecial to wrap the cooling head with an insulator
of some type, such as tin foil, or an old sock. This will help the engine retain heat and reach
200°F while it is tuned with the rich needle settings.
After a brief warm up period, disconnect the glow plug igniter and run the car on the track
for approximately 3 minutes at low speed. If the engine stalls, increase the amount of throttle
being applied slightly. If the engine stalls because it is excessively rich, close the needle valve
30° and try again. When the 3 minutes are up, shut the engine down, verify that the piston
is at the bottom of the stroke (Bottom Dead Center - BDC) and let it cool completely. Once
the engine has cooled down, close the needle valve 30°, start it again and run the car for
another 3 minutes, let it cool off with the piston at BDC. Repeat 3 more times for a total of 15
minutes (ve 3 minute cycles), keeping an eye on the temperature and making sure it is in the
low 200° range. Now increase the run time to 4 minute intervals and close the needle valve
as needed to prevent the engine from running overly rich. Vary the RPM, gradually increasing
speed, and make sure that the temperature is in the low 200° F range. Run at 4 minute
intervals, ve cycles, for a total of 20 minutes. After this the engine is ready for race tuning.
NOTE: During the rst few cycles, it is important that you use smooth throttle inputs
and do not “spike” the throttle to protect the bearings.
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Exhaust
Gasket
Glowplug
Retaining Screw
O-Ring
O-Ring
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Pliers
Glow Plug Igniter
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Approx. 0.5mm open
factory setting with the
restrictor removed.
Fuel
Fuel Tank Side
approx 1mm
Deliver fuel to the carburetor
High speed needle position when
starting the engine.
Needle
30º
Close the high speed
needle approximately
30° as needed. This
procedure will be repeated
several times throughout
the break-in process.
Idle Screw
High Speed Needle
Low Speed Needle
Open
Close
Close
Open
HIGH SPEED NEEDLE
LOW SPEED NEEDLE
More fuel
Less fuel
More fuel Less fuel
Carburetor Body
Slide Valve
Carburetor Body
Dirt and dust may lodge in marked places
7
8
17 18
The following procedure is recommended for this engine when the ProTek R/C P3,
PTK-2060 or PTK-2090 tuned pipe and fuel containing up to 30% nitromethane are used.
• Identify and note the ywheel position when the piston is at Bottom Dead Center (BDC).
• Fill the tank completely with fuel.
• Check the glow plug and verify that the lament glows bright red when the igniter is attached.
The carburetor is set at the factory as shown in the images below. Double check the
settings before you start the engine.
• The high speed needle (needle valve) is set approximately 3-turns open from the fully
closed position.
• Idle gap is set approximately 0.5mm open.
• The opening should be approximately 0.5mm with the restrictor removed.
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Exhaust
Gasket
Glowplug
Retaining Screw
O-Ring
O-Ring
Chamfer inside edges of bearers
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Element glows when energized
Pliers
Replace the plug when the
element does not glow or is
burnt out.
Glow Plug Igniter
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Approx. 0.5mm open
factory setting with the
restrictor removed.
approx 1mm
High Speed Needle
Carburetor Body
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
Dirt and dust may lodge in marked places
7
8
Piston
Near TDC
When the engine is hot.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Do not allow
bottom of crankcase
to touch chassis
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Dirt and dust may lodge in marked places
Piston
Near TDC
When the engine is hot.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Approx. 0.5mm open
factory setting with the
restrictor removed.
Carburetor Body
Ball Link
Dirt and dust may lodge in marked places
• Low speed needle (metering needle) and mid needle (mixture control valve) are set at the
basic position (refer to P23).
• Switch the transmitter on and make sure that the linkage moves correctly.
• Pre-heat the engine to approximately 150°-160°F (66º-71°C) using an engine heater or heat
gun before starting.
• Plug the stinger on the exhaust and
turn the engine over with the starter
box to draw fuel into the engine.
• Now connect the glow plug igniter to
heat the plug and start the engine.
If the engine does not start, or
stalls out right after started, try
the following:
Set the high speed needle approximately 2.5 turns open from the fully closed position. Do
not force the high speed needle to turn beyond a lightly closed position.
Set the throttle opening a little wider than the factory setting by adjusting the idle screw
(throttle stop screw).
• When the engine starts, warm it up using smooth throttle inputs, increasing the rpm to
medium speed and back to a fast idle in the neutral position with the mixture set rich.
Leave the glow plug igniter connected, and keep the wheels of the car off the ground.
The slightly rich mixture will provide adequate lubrication and cooling indicated by profuse
exhaust smoke.
Piston
Cylinder Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Exhaust
Gasket
Glowplug
Retaining Screw
O-Ring
O-Ring
Chamfer inside edges of bearers
Rotate the retainer
nut gently until it stops
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Element glows when energized
Pliers
Replace the plug when the
element does not glow or is
burnt out.
Glow Plug Igniter
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Approx. 0.5mm open
factory setting with the
restrictor removed.
Fuel
Fuel Tank Side
approx 1mm
Deliver fuel to the carburetor
High speed needle position when
starting the engine.
Needle
30º
Close the high speed
needle approximately
30° as needed. This
Idle Screw
High Speed Needle
Low Speed Needle
HIGH SPEED NEEDLE
LOW SPEED NEEDLE
Slide Valve
Carburetor Body
Low Speed Needle
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
First rotate the mid needle until its slotted
head is ush with the carburetor body. This is the
standard position.
5.5 turns out. Make adjustments with the slide in the open position.
Dirt and dust may lodge in marked places
7
8
Piston
Near TDC
When the engine is hot.
Low Speed Needle
(Metering Needle)
Idle Screw
(Throttle Stop Screw)
Mid Needle
(Mixture Control Valve)
High Speed
Needle
(Needle Valve)
Thermo Insulator
Carburetor Restrictor (Venturi)
Ball Link
Slide Boot
Retaining Screw
O-Ring
O-Ring
Do not allow
bottom of crankcase
to touch chassis
Chamfer inside edges of bearers
Tighten a further
120º - 180º
High Speed
Needle
Open
Close
approx 0.5mm
Turn the high speed needle clockwise
until it stops. This is the fully closed
position. Do not force it to turn further.
Approx. 0.5mm open
factory setting with the
restrictor removed.
approx 1mm
High Speed Needle
Carburetor Body
Low Speed Needle
Rotate the low speed needle until the head
sticks out 0.5mm from the ball link body.
This is the standard position.
Ball Link
Dirt and dust may lodge in marked places
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