21TM-T .21 Engine - Manual

It is of vital importance, before attempting to operate your
engine, to read the general 'SAFETY INSTRUCTIONS
AND WARNINGS' in the following section 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.
SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
The advice which follows 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.
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 or abused. 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.
WARNINGS
NOTES
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.
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.
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.
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.
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.
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 those
of joint 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.
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.
Piston
Cylinder
Liner
Crankshaft
Near TDC
Slight taper
When the engine is cold.
When the engine is hot.
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.
ABOUT 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 as
long and engine life will be shortened.
Items necessary for starting
TOOLS, ACCESSORIES, etc.
The following items are necessary for operating the engine.
FUEL FILTER
To installed in the fuel line between fuel
tank and carburetor to prevent foreign
matter from entering the carburetor.
GLOWPLUG IGNITER
Commercialy available handy glowplug
heater in which the glowplug battery and
battery leads are integrated.
FUEL PUMP
For filling the fuel tank, a simple,
polyethylene "squeeze" bottle, with a
suitable spout, is required.
Heatsink Head
Crankcase
Mounting Lugs
Exhaust
Rear Adaotor
Carburetor
Type 11K
Crankshaft
BASIC ENGINE PARTS
CARBURETOR CONTROLS
The Needle-Valve:
Four adjustable controls are provided on this
carburetor.
For adjusting the mixture strength when the throttle
is fully open.
The Throttle Stop Screw:
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.
ENGINE INSTALLATION
STARTING THE ENGINE & RUNNING-IN ('Breaking-in)
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.
Standard accessories
Glow Plug LC3
Exhaust Seal Ring 1pc.
MAX-21TMw/T-MaxxorRevoManifold
T-Maxx and Revo are trademarks of Traxxas Corp.
These engines are designed especially to power
the T-Maxx or Revo. Purposely designed LC3
glow plug is supplied with the engine for
improved power, fuel economy and durability.
The carburetor offers easy handling as well as
high performance.
Exhaust Manifold for Revo
Exhaust Manifold for T-Maxx
TOOLS
O.S. SPEED DRIVER TOOLS
O.S. SPEED PLUG WRENCH
O.S. SPEED FLYWHEEL KEY
O.S. SPEED FLYWHEEL PULLER
The connection between the fuel tank and the engine.
2.5mm ID
O.S. SPEED SILICONE FUEL LINE
(optional extra)
O.S. SPEED CLUTCH WRENCH & ADJUSTER
MAX-21TM-T
11K
11K-R
CARBURETOR CONTROLS 11K, 11K-R
Metering Needle
Throttle Stop
Screw
Mixture Control Valve
Needle Valve
Thermo Insulator
The Mixture Control Valve:
For changing the mixture strength at mid speed and
acceleration. (Do not rotate the screw more than one
turn.)
21TM-R
First, remove the original
engine, from the engine
mount.
Install the engine on the
engine mount with ground
wire.
Install the flywheel and
clutch.
T-Maxx
Revo
Install the electric starter taken from the original engine.
Install the manifold supplied with the engine.
Adjust the plastic ball end
so that the throttle linkage
may be connected correctly.
T-Maxx
Revo
Adjust the stopper end so that the throttle linkage may
be made correctly.
Finally, connect the wire
for glow plug heating to
the glow plug.
T-Maxx
Finally, insert the wire for
heating the glow plug.
For long life and high performance, every engine
needs to be 'run-in' or 'broken-in'. With care, running-in
of the MAX-21TM can be carried out with the engine
installed in the vehicle.
Be sure to install the air-cleaner on the carburetor and
use a muffler-pressurized fuel system.
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, means that fuel
'head' at the carburetor can vary and upset
running.Therefore,it is recommended that a muffler
pressurized fuel feed system be used.
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.
Fill the tank completely with fuel.
Temporarily remove the glowplug to check that it
glows bright red when energized.
The carburetor on this engine has been set at the
starting setting when the engine leaves the factory.
Switch on the transmitter, and check that all the
linkage moves correctly.
When the engine starts, first allow it to operate in short
runs on its very rich starting settings, with the glowplug
battery still connected and with its 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˚.
Repeat this procedure again until five 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
Control Valve 30˚.
30˚
Needle
30˚
30˚
The position of the
needle-valve when starting the
Close the needle-valve
approx. 30˚ after running
the vehicle for every one
full tanks of fuel. Repeat
this procedure around five
times.
Note:
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 or
the fuel being changed, especially to high nitro
fuel, the complete running-in should be repeated.
Fuel
Warning!
Do not touch rotating parts, engine and silencer
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, then shut it
off completely with the trim lever
on the transmitter.
To cut off the fuel supply, pinch
the fuel delivery tube to the
carburetor.
FINAL ADJUSTMENT
Type 11K
Final adjustment should be carried out only after the
running-in has been completed.
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 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 30˚.
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 30˚. If, on
the other hand, the engine tends to speed up
momentarily and then cut out abruptly when the
throttle is opened, the idle mixture is too lean.
Correct this by turning the Metering Needle
counter-clockwise 30˚.
NOTE:
Metering Needle adjustment should be made in
steps of not more than 30˚, 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.
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.
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.
Finally, beyond the nominal break-in period, a slight
readjustment toward a leaner needle setting may be
required to maintain maximum performance.