Duratrax MAXIMUM MT Installation and operating instructions

TM
Warranty
• DuraTrax®will warranty this kit for 90 days after the purchase date from defects in materials or workmanship. DuraTrax
will either repair or replace, at no charge, the incorrectly made part.
• Make sure you save the receipt or invoice you were gi en when you bought your model! It is your proof of purchase
and we must see it before we can honor the warranty.
• To return your Maximum MT for repairs co ered under warranty you should send your truck to:
Hobby Ser ices
1610 Interstate Dri e
Champaign, Illinois 61822
Attn: Ser ice Department
Phone: [phone]:00 am - 5:00 pm Central Time M-F
E-mail: [email protected]
Before Building:
We want the building and operating of this ehicle to be a success, so BEFORE remo ing any parts from the parts bags
please read this manual thoroughly and watch the included ideo to familiarize yourself with the model. If for any reason
you think this model is not for you, return it to your dealer immediately. PLEASE NOTE: Your hobby dealer cannot accept
a return on any model after assembly has begun.
ASSEMBLY AND OPERATION MANUAL
© Copyright 1999 Printed in USA DTXZ1052 For Kit DTXC0064/DTXD64**

Introduction.................................................................................2
Safet Precautions .....................................................................2
Helpful Hints................................................................................2
Stress-Tech™Parts Guarantee...................................................2
Repair Service.............................................................................2
Specification & Description Changes.......................................3
Screw Information ......................................................................3
Required Items for Completion .................................................3
Tools You Will Need....................................................................3
Finishing the RTR Version.........................................................4
Assembl of the Pre-Built Version............................................7
Preparing the Radio S stem......................................................7
Steering Servo Assembl ..........................................................7
Assembling the Radio Tra .......................................................8
Installing the Throttle Servo ....................................................10
Throttle & Brake Linkages .......................................................10
Radio Adjustments ...................................................................11
Prepare the Engine ...................................................................12
Finishing....................................................................................13
Carburetor Settings ..................................................................14
Breaking-In the Engine ............................................................15
Running the Engine..................................................................15
Engine Maintenance .................................................................16
Performance Tuning .................................................................17
Maintenance Tips......................................................................18
Engine Trouble Shooting .........................................................19
Thank you for purchasing the DuraTrax Maximum MT. This
manual contains the instructions you need to build, operate,
and maintain your new nitro R/C truck. Read o er this manual
thoroughly before building or operating the Maximum MT.
When the safety precautions are followed, the Maximum MT
will pro ide years of enjoyment. Use care and good sense
at all times when operating this radio controlled truck.
Failure to use this ehicle in a safe, sensible manner can
result in injury or damage to property. You and you alone
must insure that the instructions are carefully followed and
all safety precautions are obeyed.
• Do not operate the Maximum MT near people. Spectators
should be behind the dri er or at a safe distance away
from the ehicle.
• The engine and exhaust system produces quite a bit of
noise. If you are disturbed by the amount of noise this
truck produces, wear ear protection such as earplugs.
Do not run this ehicle when or where it can disturb others.
• The engine and exhaust system can become ery hot.
A oid touching any of these parts during use and until
they ha e cooled down.
• Model engine fuel is poisonous. Make sure you read and
follow all of the precautions on the fuel container. Keep
fuel out of the reach of children.
• Model engine fuel is flammable and when ignited has a
flame that is difficult to see. A oid sparks, flames,
smoking, or any other ignition source when fuel is near.
• The engine emits carbon dioxide just like real cars. Do
not operate this model indoors.
• Before turning on the transmitter, make sure that no one
else is on your frequency.
• A oid working o er a deep pile carpet. If you drop a small
part or screw, it will be difficult to find.
• Place a mat or towel o er your work surface. This will
pre ent parts from rolling off and will protect the
work surface.
• A oid running the truck in cold weather. The plastic and
metal parts can become brittle at low temperatures. In
addition, grease and oil become thick, causing premature
wear and poor performance.
• Test fit all parts before attaching them permanently.
We ha e engineered the Maximum MT to take the rough
and tumble abuse that makes R/C fun. We are so confident
of the quality and durability of the Stress-Tech™plastic parts
that we will replace any Stress-Tech plastic part you break
during the first 6 months you own the truck. Just send in the
part to us and we will send you a Free replacement. Please
see the Maximum MT parts list for the items co ered under
the Stress-Tech guarantee.
To recei e your free replacement part please send the
following to the Hobby Ser ices address listed on the co er
of this manual:
• The broken part must be included.
• The part number and description of the broken part.
• Dated copy of your in oice or purchase receipt.
• Your name, phone number and shipping address.
Repair ser ice is a ailable anytime.
• After the 90 day warranty, you can still ha e your
Maximum MT repaired for a small charge by the experts
at DuraTrax’s authorized repair facility, Hobby Ser ices,
at the address listed on the co er of this manual.
REPAIR SERVICE
STRESS-TECH™PARTS GUARANTEE
HELPFUL HINTS
SAFETY PRECAUTIONS
INTRODUCTION
TABLE OF CONTENTS
2

To speed up the repair process, please follow the instructions
listed below.
1. Under most circumstances return the ENTIRE system: truck
and radio. The exception would be sending in a Stress-Tech
part. See the instructions under the Stress-Tech Guarantee.
2. Make sure the transmitter is turned off, all batteries are
remo ed, and fuel is drained from the tank.
3. Send written instructions which include: a list of all items
returned, a THOROUGH explanation of the problem and
the ser ice needed, and your phone number during the
day. If you expect the repair to be co ered under
warranty, be sure to include a proof of date of purchase
(your store receipt or purchase in oice).
4. Also be sure to include your full return address.
All pictures, descriptions, and specifications found in this
instruction manual are subject to change without notice.
DuraTrax maintains no responsibility for inad ertent errors
in this manual.
Do not use too much force when tightening self-tapping
screws into plastic. O ertightening will cause the threads in
the plastic to strip. We recommend that you stop turning a
self-tapping screw when you feel some resistance as the
head of the screw comes in contact with the plastic. A oid
using powered screwdri ers when assembling this kit. They
tend to o ertighten the screws. Do not use thread locking
compound on any self-tapping screws. The thread locking
compound may damage the plastic. IMPORTANT: Use
thread lock on any fastener that is threaded into metal or
fastened with a nut. Vibration from the engine will cause the
screws to loosen if thread locking compound is not used.
The illustration abo e shows how to identify the types of
screws used throughout this instruction manual.
To operate the Maximum MT these items are required:
• Glow plug starter (Hobbico®Hot-Shot™ 2 -HCAP2520)
• Fuel bottle (DuraTrax Kwik-Pit™Bottle - DTXP0125)
• Fuel (DuraTrax Red Alert™fuel - DTXP0520)
• Air filter oil
• Tie straps
• Hobby knife with #11 blade (HCAR0105)
• Glow plug wrench (DTXR1170)
• It is also helpful to ha e a couple of extra glow plugs
on hand. We recommend the O.S®. #A3 plug (OSMG2690)
All of these items are available in a Nitro Starter Pack
from DuraTrax - DTXP0200).
For the Pre-Built version of the Maximum MT, ou will also
need:
• 2-channel radio with (2) standard ser os
• (12) “AA” batteries - (4) for the recei er and (8) for the
transmitter
• Small bottle of thread locking compound (GPMR6060)
To assemble the Pre-Built ersion (DTXC0055), you will
need the following tools:
• Phillips head screwdri er
• Flat blade screwdri er
• Needle-nose pliers
• Wire cutters
• Hobby knife (HCAR0105), #11 blades (HCAR0211)
• Drill with 1/4", 1/8", 5/64" (or 6mm, 3mm, 2mm) bits
TOOLS YOU WILL NEED
REQUIRED ITEMS FOR COMPLETION
3mm
14mm
M3x14 Screw
3mm
14mm
M3x14
Self-Tapping
Screw
SCREW INFORMATION
SPECIFICATION & DESCRIPTION CHANGES
3

❏1. Remo e the transmitter and truck from the box.
❏2. Remo e the twist-tie from the recei er antenna. (The
recei er antenna looks like a bundled thin wire that is
attached to the recei er.) Thread the recei er antenna
underneath and through the hole in the radio plate next to
the recei er switch.
❏3. Remo e the antenna tube from the parts bag. Thread
the recei er antenna through the antenna tube. The antenna
will be longer than the antenna tube. DO NOT COIL OR CUT
THE ANTENNA. Press fit the antenna tube through the hole
in the radio plate. Place a 1/8" long piece of fuel tubing o er
the antenna tube and wire to secure in place. TIP: Run the
antenna through your fingers to straighten out kinks before
running through the antenna tube.
❏4. Remo e the air filter and tie strap from the parts bag.
Thoroughly soak the air filter foam with some oil (not
included) and then squeeze out the excess oil. A light machine
oil (like 3-IN-ONE™) will work well. Special oils made for air
filters are also a ailable in most hobby and motorcycle
shops. Place the air filter onto the carburetor and secure it
in place with the tie strap. Cut off the excess part of the
strap.
❏5. Remo e the four screws from the top of the radio plate
and remo e the recei er battery holder.
4
FINISHING THE RTR VERSION (DTXD64**)

❏6. Remo e the recei er battery holder from the radio box.
Install (4) “AA” (included) into the battery holder in the
configuration molded into the battery holder.
❏7. Re-install the recei er battery holder under the radio
plate. Make sure that the recei er switch is in the off
position. Plug the connector on the recei er battery into the
socket on the recei er switch. Tuck the wires between the
ser o and recei er battery so they will not get caught on
anything.
❏8. Remo e the transmitter antenna from the holder and
screw it into the hole on top of the transmitter.
❏9. Slide open the battery door on the bottom of the
transmitter and remo e the transmitter battery holder. Place
8 “AA” batteries into the holder in the configuration molded
into the plastic on the battery holder. Re-install the
transmitter battery holder into the transmitter and re-install
the battery door.
❏10. Turn on the transmitter using the switch on the back
(see the photo with Step 8), The green light on the side of
the transmitter should light up. If there is no light on, turn the
transmitter off and check to ensure that the battery holder is
making contact with the copper contacts on the inside of the
battery compartment. Make sure the batteries are installed
correctly. Turn the transmitter on and check for the green
indicator light. If the green light appears, turn off the
transmitter.
❏11. Remo e the plastic from the outside of the body.
Apply the decals if desired. For decal placement, see the
photos on the box top.
5

❏12. Assemble the rollbar as shown using ten 2.6 x 6mm
self-tapping screws.
❏13. Drill six 1/4" (6mm) holes in the body using the
molded-in dimples as guides. Install the rollbar onto body as
shown using six 2.6 x 6mm self-tapping screws and the
included collars.
❏14. Drill two 1/4" (6mm) holes in front of body using the
molded-in dimples as guides. Install the front brush guard
as shown with two 2.6 x 6mm self-tapping screws and the
collars included.
❏15. Drill one 1/8" (3mm) hole in each side of the body
using the molded-in dimple as a guide, and one 5/64"
(2mm) hole 7/16" (11mm) below and 7/16" back from first
hole (use the pegs on the mirror as a guide). Install the
mirrors as shown with the collars pro ided.
❏16. Remo e the body clips from the parts bag. Place the body
on the body mounts. On each body mount place a body clip.
Congratulations, you ha e completed preparations!
Before running your new truck, please take the time to
carefully read the instructions and watch the ideo before
running and breaking-in the engine. Make sure you follow
the safety precautions and most of all...HAVE FUN!
6

7
1. Install the batteries in the transmitter and
the recei er battery holders.
2. Extend the transmitter antenna.
3. Connect the steering ser o, throttle ser o
and recei er battery to the recei er.
4. Extend the recei er antenna.
5. Adjust the ser o trims of the transmitter to
the neutral position.
6. Switch on the transmitter.
7. Switch on the recei er.
8. Operate the steering and throttle control.
Make sure the ser o arms mo e in
proportion to the mo ement of the
steering wheel and throttle trigger.
9. Switch off the recei er, then the transmitter.
Before installing the radio s stem in the
pre-built DuraTrax Maximum MT, read the
manufacturer’s instructions manual and
follow the instructions shown below.
Ser o Arm
Steering
Ser o
Throttle Ser o
Recei er Battery Holder
4-AA Batteries
Transmitter
5
6
1Antenna 4
8-AA Batteries
1
Recei er
3
Recei er
Switch
7
Antenna
2
8
PREPARING THE RADIO SYSTEM
ASSEMBLY OF THE PRE-BUILT VERSION (DTXC0064)
Place a check mark in the check boxes after each step is
completed.
❏1. From bags PA001 and PA003, remo e (8) 3 x 8mm
self-tapping screws, and the (2) L-shaped ser o mounts.
❏2. Attach the ser o mounts to the steering ser o with (4)
3 x 8mm self-tapping screws. Note that the ser o spline will
mount towards the rear of the truck.
❏3. Attach the steering ser o assembly to the chassis with
(4) 3 x 8mm self-tapping screws in the holes pro ided as
shown abo e.
STEERING SERVO ASSEMBLY

❏4. From bag PA001, remo e the steering rod. Note the
shape of the rod.
❏5. Use a 3 or 4 hole ser o arm from your radio system. A
1, 2, or 4-armed ser o arm will work. Cut off all but one of
the arms by scoring both sides of the ser o arm with a
hobby knife and using pliers to snap off the arm.
❏6. Put the steering rod into the third hole from the center
of the ser o arm (approximately 5/8" or 16mm). You may
need to enlarge the hole in the ser o arm with a 5/64"
(2mm) drill or a hobby knife.
❏7. Place the rod connector through the top of the middle
hole in the steering arm. Place a small amount of thread
locking compound onto the threads of the rod connector.
Do not to overtighten the nut, the rod connector must
swivel freel . Install the 2mm nut onto the bottom of the rod
connector. Install a 2mm set screw into the top of the rod
connector. Note: When installing the set screw, make sure
not to thread it in too far because the steering rod must pass
through the hole on the side of the rod connector.
❏8. Slip the steering rod through the hole in the rod
connector that is already installed on the ser o sa er. (Use
the screw that came with your radio system to attach the
ser o arm to the steering ser o.) Do not tighten the set
screw on the rod connector. You will make the steering
adjustments later.
❏1. From bag PA002, remo e all of the parts included; the
radio tray, the (2) radio tray mounts, and the (8) 3 x 8mm
self-tapping screws.
❏2. Place foam tape on the bottom of the radio plate. This
will secure the recei er battery into place when the radio
plate is installed.
ASSEMBLING THE RADIO TRAY
8

❏3. Using the pro ided double-sided tape, attach the radio
recei er to the top of the radio tray. To find the top of the
radio tray, place the large circular hole to the lower left as
shown. Make sure that the recei er is installed in the space
between the sets of screw holes as shown abo e.
❏4. Attach the switch from your radio system so it is abo e
the top of the radio plate (make sure the switch is in the OFF
position). Remo e the two screws on the top of the switch.
Place the switch plate on top of the radio tray, the switch
body on the bottom of the radio tray and then reinsert the
screws from the top.
❏5. Attach the radio tray mounts as shown to the chassis
with (4) 3 x 8mm self-tapping screws.
❏6. Remo e from your radio system the 4-cell recei er
battery holder and install (4) “AA” batteries (not included).
The negati e sides of the batteries are placed against the
springs in the battery holder. Plug the connector on the
recei er battery holder into the connector on the switch. Make
sure the switch is in the OFF position. Place the recei er
battery holder between the radio plate posts.
❏7. Plug the steering ser o, throttle ser o, and switch into
the recei er. See your radio instructions to determine which
channel is steering and which channel is throttle. The
recei er switch plugs into the socket labeled “Battery,”
“Batt,” or “B.”
❏8. Attach the radio tray to the radio tray posts with (4)
3 x 8mm self-tapping screws.
9

❏9. Fit the antenna tube through the radio tray and press
fit the antenna tube into the radio tray post. Thread the
recei er antenna through the antenna tube. The recei er
antenna wire will be longer than the antenna tube. DO NOT
CUT OR COIL THE ANTENNA. Use tape or cut 1/4" long
pieces of fuel tubing to attach the lefto er antenna wire to the
outside of the antenna tube. Use a hobby knife or drill to cut
a hole in the body to route the antenna tube through.
❏1. From bags PA001 and PA003, remo e the (2) throttle
ser o mounts and (8) 3 x 8mm self-tapping screws.
❏2. Use the (4) 3 x 8mm self-tapping screws to attach the
throttle ser o to the throttle ser o mounts.
❏3. Use the (4) 3 x 8mm self-tapping screws to attach the
throttle ser o and the mounts to the chassis. Make sure that
the ser o spline is towards the rear.
❏1. From bags PA001 and PA003, remo e the brake rod,
the throttle rod, the brake spring, (3) 3 x 3mm set screws,
the 2mm nut, the rod connector, and (3) 2mm collars.
❏2. From your radio system remo e a large, X-shaped
ser o arm. Remo e two of the ser o arms as shown. Install
the rod connector in the last hole on the arm as shown in the
diagram abo e (approximately 3/4" or 18mm). You will need
to enlarge the hole with a hobby knife or a 5/64" (2mm) drill
to fit the rod connector. Apply a small amount of thread
locking compound (not included), on the nut to hold it in
place. Secure the rod connector to the ser o arm with the
2mm nut. Do not tighten the nut completely. The rod
connector should swi el easily.
Rod Connector
3/4"
(18mm)
Rod Connector
THROTTLE & BRAKE LINKAGES
INSTALLING THE THROTTLE SERVO
10

❏3. Insert the brake rod as shown in the photo. Insert the
brake rod into the ser o arm from the bottom, into the
second hole from the outside of the arm (approximately 5/8"
or 16mm from the center).
❏4. Place the ser o arm on the throttle ser o as shown in
the photo abo e and place the brake rod through the brake
le er. Do not install the ser o arm screw yet. You will need
to make adjustments before running your truck.
❏5. Insert the throttle rod into the outer hole in the
carburetor arm. Assemble in order, a 2mm collar and the
throttle spring. Next insert the throttle rod through the rod
connector on the throttle ser o.
❏6. Install a 2mm collar at the end of the brake rod and
another 2mm collar at the end of the throttle rod. Place a
small amount of thread locking compound on two of the (3)
3 x 3mm set screws and thread them into the 2mm collars.
Do not tighten the set screws all the way. In the next section
we will make adjustments to the collars.
• Turn on the transmitter first, then the recei er.
• Center the trims of the throttle and steering channels (see
your radio system manual for the location of the trim
adjustments).
Steering Linkage Set Up
A) Remo e the arm from the steering ser o and re-install
the arm facing straight up (see photo abo e).
B) Position the front wheels so they are aimed “straight
ahead” (note that the tires are aligned slightly inward – this
is called toe-in).
C) When the wheels are straight, tighten the set screw on
the rod connector. Attach the ser o arm with the ser o arm
screw from your radio system.
RADIO ADJUSTMENTS
11

Throttle Linkage Set Up
A) With the radio system still on, set the throttle in the
neutral position.
B) Remo e the ser o arm from the throttle and replace the
arm so that it is aligned with the centerline of the throttle
ser o case.
C) The brake le er should be perpendicular (i.e. straight) to
the centerline of the chassis as shown abo e.
D) Tighten the 2mm collar on the brake rod so that it is 3/32"
(2mm) away from the brake le er.
E) Push the throttle rod with your finger until the carb closes
as far as possible (the carb will not close completely which
is normal).
F) Tighten the set screw on the outer collar and cut the
throttle rod flush with the outer 2mm collar.
G) Mo e the throttle spring next to the rod connector.
H) Tighten the inner 2mm collar next to the throttle spring
without compressing the spring.
I) Attach the throttle ser o arm with the screw included with
your radio system.
❏1. Remo e the fuel tank by taking out the two screws on
the bottom of the chassis.
❏2. Remo e the fuel line, air cleaner, and tie-strap from the
parts bag.
❏3. Cut the fuel line in half. Route one of the lines from the
nipple on the top of the muffler to the top of the fuel tank.
Route the other fuel line from the nipple on the carburetor to
the bottom of the fuel tank. Ensure that the fuel line is not
kinked anywhere along the line. You may ha e to shorten
the line to eliminate kinks.
PREPARE THE ENGINE
12

❏4. Re-install the fuel tank.
❏5. Remo e the air filter and tie strap from the parts
bag. Thoroughly soak the air filter foam with some oil
(not
included) and then squeeze out the excess oil. A
light
machine oil (like 3-IN-ONE) will work well. Special
oils made for air filters are also a ailable in most
hobby and motorcycle shops. Place the air filter onto
the carburetor and secure it in place with the tie strap.
Cut off the excess part of the strap.
❏1. Bundle all of the wires around the recei er together
with a tie-strap or a twist-tie (not included in the kit).
❏2. Remo e the clear co ering from the outside of the body.
Apply decals to the body if desired. For decal placement,
see the photos on the box top.
❏3. Assemble the rollbar as shown using ten 2.6 x 6mm
self-tapping screws.
❏4. Drill six 1/4" (6mm) holes in the body using the
molded-in dimples as guides. Install the rollbar onto body as
shown using six 2.6 x 6mm self-tapping screws and the
included collars.
FINISHING
13

❏5. Drill two 1/4" (6mm) holes in front of body using the
molded-in dimples as guides. Install the front brush guard
as shown with two 2.6 x 6mm self-tapping screws and the
collars included.
❏6. Drill one 1/8" (3mm) hole in each side of the body
using the molded-in dimple as a guide, and one 5/64"
(2mm) hole 7/16" (11mm) below and 7/16" back from first
hole (use the pegs on the mirror as a guide). Install the
mirrors as shown with the collars pro ided.
❏7. Mount the body on the body posts and secure the body
to the truck with (4) body clips.
Congratulations, you ha e completed assembly! Before
running your new truck, please take the time to carefully
read the instructions and watch the ideo before running
and breaking-in the engine. Make sure you follow the safety
precautions and most of all...HAVE FUN!
The High-Speed Needle
The “high-speed” needle is sticking up from the side of the
carb. It is located in the brass housing, just abo e the fuel
inlet. It controls the fuel to air mixture of the carb. The
needle is pre-set for break-in from the factory at 2-3/4 turns
out from the fully closed position of the carb. Once the
engine is broken-in, the high-speed needle would typically
run from 2 to 2-1/2 turns out from closed, depending on the
weather, humidity and altitude abo e sea le el. To richen
turn the needle counterclockwise, to lean turn the needle
clockwise.
CARBURETOR SETTINGS
14

The Low-Speed Needle
The “low-speed” needle is the screw in the middle of the
throttle arm. It controls the fuel to air mixture at low throttle
settings. There is a simple way of adjusting the low-speed
needle correctly called the “pinch test.” With the engine at
idle, pinch the fuel line and listen to how the engine speeds
up or slows down. If the engine increases its speed for
about 2 or 3 seconds and then loses speed, the needle is
set correctly. If the engine loses RPM quickly, it is set too
lean and the low-speed needle needs to be opened
(counterclockwise) to richen the mixture. Pinch again to
check the mixture. If the engine takes longer than 4 seconds
to slow down, lean (clockwise) the low-speed needle and
then pinch again to check the mixture.
The Throttle Stop Screw
On the front of the carburetor, there is a black screw. This is
called the idle stop screw. This increases or decreases the
idle RPM without changing the fuel to air mixture. The barrel
should be approximately 1.5mm (between 1/32" and 1/16")
from fully closed.
To insure long life and good performance from your Torq .16
engine, you MUST break-in the engine. The break-in period
is critical for long life of the internal parts of the engine. This
should be done o er the first 4 or 5 tanks of fuel.
Some Things To Remember During Break-In
1. Run with the body off. This will keep the engine cooler.
2. Keep the air cleaner on at ALL times
3. Run on a smooth, hard surface. An empty parking lot is
perfect.
4. Use the same fuel that you will use for normal running.
5. Resist the urge to accelerate and decelerate the truck
quickly.
6. Break-in puts stress on the glow plug and you can burn
it out during break-in. Make sure you ha e an extra plug
or two on hand.
7. Do NOT o erheat the engine. You can check the head
temperature by using one of the temperature gauges
that are a ailable or by putting a drop of water on the
top of the cylinder head. If the water boils away
immediately, shut off the engine and allow it to cool. If it
takes more than 5 seconds to boil away, the engine is
at proper running temperature for break-in.
Before running the engine, read the manual and watch the
engine ideo that came with this kit.
There are several simple steps to starting the engine:
1. Install a glow plug. This threads into the top of the
cylinder head.
2. Fill the tank - Fill the tank almost to the top. Lea e a little
air at the top of the tank.
3. Prime the engine - Use the primer button on the fuel tank
to force the fuel through the fuel line. Watch the fuel go
through the line and when it gets to the carburetor, press
the primer button once more to get fuel into the engine.
4. Open the high speed needle al e exactly 2-3/4 turns out
(counterclockwise) from fully closed. The high-speed
needle is sticking up from the carburetor inside the
brass housing. All of the carburetor settings are
adjusted with a flat bladed screwdri er. If you ha e
pre iously run the truck, keep the same needle al e
setting that you used on your last run.
5. Start the engine by pulling the recoil - Use short, quick
pulls. DO NOT pull the recoil starter’s string to the end.
You only need 10 to 12 inches of pull to start the engine.
Sometimes it is helpful to start the engine at around half
throttle. Ha e a friend pull back on the throttle some while
you start the engine. This may be an indicator that the low
speed needle setting needs to be adjusted. When the
engine starts, immediately return the throttle to idle. If this is
not done the engine can o er-re and cause engine
damage. If the engine is difficult to turn over with the
recoil starter, especiall if it is brand new, loosen the
glow plug a half turn before starting the engine. This
allows some compression to escape, but the engine will
still start. Make sure you tighten the glow plug after the
engine starts. If the recoil starter is still difficult to pull, the
engine is flooded – there is too much fuel inside the engine.
Remo e the glow plug and air cleaner, then turn the engine
upside down and pull the recoil 5 or 6 times. This will clear
the engine of fuel, and you will notice the recoil pulls easier.
Replace the glow plug and repeat the starting procedure.
Fuels
Use fuels that are specially formulated for car and truck
engines. DuraTrax Red Alert fuel is specially formulated for
truck engines like the Torq .16.
How To Stop Your Engine
You may ha e been wondering how to stop the engine. All
you ha e to do is pinch the fuel line that runs to the
carburetor and from the bottom of the fuel tank. Pinching
this will restrict the fuel flow and the engine will quit within a
few seconds.
RUNNING THE ENGINE
BREAKING-IN THE ENGINE
15

16
The First Tank
Your first tank of fuel should be running the truck at a ery
rich high-speed needle al e setting. This allows the fuel to
carry as much oil as possible into the engine to lubricate the
internal parts during the break-in.
1. Open the needle al e 2-3/4 turns from fully closed
(counterclockwise). This is factory set already, but
check it to make sure. When closing the high-speed
needle, close the needle until you feel some resistance.
DO NOT o ertighten or you will damage the engine.
2. Start the engine.
3. Once the engine is started, open the high-speed needle
al e around 1/8 turn at a time, finding the setting where
the engine just barely runs. This may take a few times
adjusting the needle, running the truck away from you and
back, then adjusting the needle. The truck will perform
sluggishly and stall from time to time - that is normal.
4. Run the truck back and forth at medium speeds, slowly
accelerating and decelerating the truck.
5. After a minute or two of running, make sure the engine
is not o erheating by putting a drop of water on the
cylinder head and watching it boil away. If it boils away
immediately, stop the engine and allow it to cool. Open
the high-speed needle around a 1/4 turn before starting
again. This is a good habit to get into e ery time you run
to ensure that the engine does not o erheat during any
run. Looking at the smoke that comes out the exhaust
is also an indicator of how rich or lean the engine is
running. If there is a good amount of smoke coming out
of the exhaust, then chances are good that you are
running rich.
6. Run the truck back and forth at a medium speed until
the tank is almost out of fuel. Do not allow the tank to
run out of fuel. This leans out the engine and can cause
o erheating (See How To Stop Your Engine).
7. Stop the engine and allow the engine to cool before the
second tank. This normally takes around 10 minutes.
Tanks 2-5
Turn in the needle al e (clockwise) around 1/12 turn from
the pre ious setting. Run the truck back and forth. You
should notice that the truck will perform better during each
run. Stop the truck periodically to check for o erheating. If it
is too hot, stop the engine. Wait for it to cool, then open up
the needle al e and restart. After the 5th tank, you should
be near to the peak performance of the engine.
10 Wa s To Ensure A Long Life From Your Engine:
1. Keep your engine clean. Dirt will act as insulation on an
engine. It will not be able to shed heat as easily. Use a
good air filter to keep dirt out of your engine and clean
it often.
2. Do not o er-lean your engine.
3. Do not run your engine with little or no load. Don’t
throttle up the engine to full throttle when the wheels are
not in contact with the ground.
4. Do not o erheat the engine. This goes along with
keeping it clean and not o er-leaning the engine.
5. Do not use a fuel with a low oil content. Make sure you
use a fuel from a reputable manufacturer, such as
DuraTrax Red Alert.
6. A oid using old fuels in the engine. Always run all of the
fuel out of the engine. After running for the day, use an
after-run oil and work it into the engine by turning the
flywheel or pulling the engine recoil slowly.
7. Do not use a fuel with a nitromethane (often called nitro)
content o er 20%.
8. Do not scratch the piston or cylinder slee e. A oid
jamming something into the exhaust port when remo ing
or re-installing the clutch or flywheel. Use a special tool
called a crankshaft locking tool, which is installed in the
glow plug hole.
9. Do not use silicone sealer on the engine joints. Silicone
sealer contains acetic acid, which is corrosi e if it gets
inside your engine.
10. Do not allow any water inside the engine. This sounds
easy, but temperature changes can cause condensation
inside the engine. This is a good reason to use an
after- run oil. Store your engine inside the house, not in
a garage or shed where there will be temperature
extremes.
If you are having problems with your engine consult the
engine troubleshooting flow chart on page 16. The
following are some potential problems.
Glow Plug
The glow plug is an item that will wear out and need
replacement from time to time. It is a good idea to remo e
the glow plug before your first run, heat it and see how well
it glows. You should see a bright orange glow from the
filament. If a coil or two will not glow or the plug will not glow
at all, replace the plug. If the engine quits when you remo e
the glow starter, the plug might need to be changed,
although this may be because you are running too rich and
need to screw in your high-speed needle some. Look at the
glow plug when you are running the engine. If you see some
bubbles coming from around the plug, replace the glow plug
(copper) gasket, or both the plug and gasket. The only real
way to test a glow plug is to replace it. Make sure you ha e
a spare plug or two on hand e ery time that you run the
Maximum MT.
ENGINE MAINTENANCE

Fuel
Fuel can go bad. The main ingredient in model fuel is
methanol, which is basically an alcohol. Alcohols can
absorb water out of the air, so keep your fuel jug capped at
all times. Store your fuel out of the sunlight and in a cool
place. Bad fuel is one of the most difficult problems to
diagnose in engines. If you ha e tried e erything you can
think of to remedy an engine that is not running correctly, try
using some fresh fuel.
Fuel line is susceptible to pinhole leaks. You cannot see the
hole in the fuel line, but if you see air bubbles in the line
going to the carburetor, replace the fuel line. Another
symptom of a leak in the fuel line is a surging engine. The
properly tuned engine will surge when the air bubbles hit the
carb. It is basically leaning out the mixture.
To keep dirt out of the engine, we recommend that you use
an inline fuel filter on the fuel line running from the fuel tank
to the carburetor. Dirt can get caught in the needle seat and
cause an inconsistent running engine. If you suspect that
some dirt has lodged itself in the carb, remo e the needles
and clean the carb with denatured alcohol or fuel. It can help
to use compressed air to blow out the fuel passages as well.
Dirt can get into your carburetor and engine through the air
filter. Ensure that your air cleaner has a good seal to the top
of the carb. Periodically wash the air cleaner foam element
and re-oil the filter. Any air cleaner that has a torn element
or a bad seal should be replaced immediately.
Overheating
One of the worst things you can do to your engine is
o erheat it. The oils that lubricate the engine are carried in
the fuel. If your engine is set too lean, there will not be
enough oil in the engine to lubricate the internal parts. This
will cause premature wear in the engine and cause
damage. We ha e talked about o erheating in other parts of
this manual, but we want to stress the proper techniques to
check for o erheating. The easiest way of checking the
temperature of the cylinder head is using one of the
a ailable temperature gauges. This will gi e you a direct
reading of the cylinder head temperature. Do not let the
head temperature exceed 220° Fahrenheit (104° Celsius).
Another way of checking the head temperature is to put a
drop of water on the cylinder head. If it boils away
immediately, the high-speed needle is set too lean. If the
water boils away in 3-5 seconds, the engine is within proper
operating temperatures. If the water boils away longer than
5 seconds, the mixture is set rich which is preferable when
breaking in the engine. Otherwise lean the mixture some
and retest after a minute of running.
Ride Height: This refers to the clearance between the
ground and the chassis, both at the front and the back of the
truck. The ride height on the Maximum MT should be
approximately 2-3/8" (60mm). To determine the ride height,
drop the truck from around 6"-12" abo e flat ground. Drop
the truck, making sure it drops flat. Check where the
suspension arms come to rest. You can adjust ride by
mo ing the spring adjusters on the shock (which are at the
top of each shock spring) until the appropriate height is
achie ed after the drop test.
Toe-In Toe-Out: This refers to the angle of the front tires
when iewed from abo e when the suspension arms are
le el. If the fronts of the tires angle in, it is called “toe-in” and
if the fronts of the tires angle out, it is called “toe-out.” This
is adjusted by turning the steering rods - the rods that run
between the front hub and the ser o sa er. These are
turnbuckle type, which means you do not ha e to remo e
the rods to make adjustments in length. Turning the rod in
one direction will lengthen, turning the rod the opposite
direction will shorten. Normally a small amount of toe-in is
used to make the truck track straight at high speed. Too
much toe-in will make the truck difficult to turn as well as
reduce the o erall top speed because of tire scrub.
Sometimes a small amount of toe-out will be used to help
the steering. As a general rule use a small amount of toe-in.
Camber: Camber is the angle of the tops of the tires when
iewed from the front. Negati e camber is when the tops of
the tires are angled towards the center of the truck. Positi e
camber is where the tops of the tires are angled away from
the center of the truck. Positi e camber is ery rarely used,
if e er. A small amount of rear negati e camber is helpful to
increase traction in the rear. Negati e camber at the front
will increase stability. Camber adjustments can be made on
the Maximum MT by turning the “camber rods,” which are
the upper links on the suspension. The camber links are
also turnbuckle type. Lengthening the camber rod will add
positi e camber and shortening the camber rod will add
negati e camber.
PERFORMANCE TUNING
17

Shocks: Changes in shock oils, springs, and pre-load on the
springs can dramatically change the way the car handles. A
thicker shock oil will make the truck turn faster but reduces
o erall traction and handling o er bumpy surfaces. Thinner
oil will increase traction at the expense of steering response
and the car will tend to roll more. In general, shock oils
between 20 and 40 weight will be best for your truck. You
should experiment some to see what oils work best for your
track and dri ing style. Shock springs affect the rate that the
suspension rebounds from a bump. We ha e supplied soft
springs that work under most conditions. Other springs are
a ailable from DuraTrax. Pre-load on the springs means
that the springs are already compressed some so that the
suspension will rebound faster. Sometimes you will want to
pre-load one side when the track has turns all or mostly in
one direction, for instance an o al track. It will also increase
the ride height.
Slipper Clutch: The slipper clutch is attached to the spur
gear on your truck, the large gear on the outside of the
transmission. This clutch will slip when too much power is
sent to the wheels. It has adjustable tension by turning the
nut on the shaft. This is designed to maximize traction on
arious surfaces by slipping before the wheels do. To adjust
the slipper clutch, run the truck on the surface you plan to
race. If the rear wheels spin when full power is applied from
a stop, loosen the nut until the wheels do not spin any more.
If the wheels do not spin, tighten the nut until the wheels
spin and then loosen the nut some.
Before Each Run
• Check for loosened screws on the truck. Engine ibration
will loosen some of the screws, particularly in the engine
mount area. Use thread lock on screws that thread into
metal parts or use a metal nut.
• Inspect the air cleaner for a torn or damaged element.
Also look for dirt in the air cleaner element and wash it if
necessary.
• Check the suspension and dri e train for binding.
• Inspect all of the wires for damage. Also check the
connectors to make sure all of them are tight and in the
proper place.
• Check the fuel tank and fuel lines for leaks.
• Before starting the engine, turn on the radio and make
sure the ser os mo e easily and in the right direction.
• Before running always check the condition of your radio
system batteries and replace/recharge if necessary.
After Each Run
• Drain the fuel tank of any lefto er fuel. DO NOT return it
to your fuel jug.
• Put some after-run oil in the carb and turn the flywheel
se eral times to work the oil into the engine. This will
protect the engine from rusting, especially when stored
for a long period of time.
• Check again for loosened screws.
•CLEAN the truck. Wipe off any oils that ha e collected
on the chassis, engine end exhaust. Oils will attract dirt
on the next run.
MAINTENANCE TIPS
18
0" 1" 2" 3" 4" 5" 6" 7"
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Inch Scale
Metric Scale (mm)

19
ENGINE TROUBLE SHOOTING
The engine starts
Does the engine
turn o er easily?
Does it run
continuously?
Is fuel getting to
the engine?
Check for clogging in
the carburetor or fuel
line. Press the
primer pump and
check for fuel
spraying out of the
fuel line. If so,
replace the fuel line.
Is fuel in the
fuel line?
Is the glow plug
red hot?
Check the high speed needle
setting and prime the engine.
Is foreign matter
clogging the fuel
tank or fuel line?
Is the battery for
the glow plug
clip charged?
It should be
ready to go.
Is the high
speed needle
setting 1 to
1-1/2 turns out
from closed (if
the engine is
broken-in?)
Try starting the
engine again.
NO
NO
NO
NO
YES
YES
YES
YES
YES
Does the engine
quit when the
glow plug clip is
remo ed?
YES
YES
Clear the engine
of fuel.
NO
Reset the high
speed needle.
YES
NO
Replace the
glow plug.
Check that the
pressure line is
connected to the
muffler. The fuel
may be bad.
The engine does not start
NO
Does the engine
turn o er easily
with the glow
plug remo ed?
The engine may
be flooded.
Clear the engine
of fuel.
YES
Check that
nothing is
caught in the
engine. Check
that the the
pull starter
operates
smoothly.
NO
Press the
primer pump
and check for
fuel spraying
out of the fuel
line through a
small hole. If
so, replace
the fuel line. YES
Remo e the
obstruction from
the fuel tank or
fuel line.
NO NO Charge or
replace the
batteries.
YES
Replace the
glow plug.
Try starting the
engine again.

RECOMMENDED ACCESSORIES
DuraTrax Deluxe Glow Plug Wrench
This single, hea y-duty, plated steel tool
handles FIVE metric hex sizes: 7-, 8-, 10-, 12-
and 17mm—and includes a special 10mm
socket for pilot shafts! Threaded holes tapped
between the wrenches store up to four spare
glow plugs. DTXR1170
DuraTrax Red Alert™ 20% Racing Fuel
To make your TORQ™ 21 engine run faster,
better and longer, you need the unique
formula of DuraTrax Red Alert. Red Alert
contains 20% nitro plus a carefully race-tested
blend of castor and synthetic oils. DTXP0600
DuraTrax Nitro Starter Set
This set includes e erything you need to start
racing. 5-way glow plug wrench, 1 qt. of Red
Alert fuel, Hobbico®glow starter w/charger,
fuel bottle and glow plug. DTXP0200
DuraTrax Crankshaft Locking Tool
Remo e your engine’s clutch safely with this
easy to use, anodized metal tool. Works
with all .10 to .21 car and buggy engines.
DTXR1100
DuraTrax XL Field Bag
Keep your gear loaded and race ready with
the XL field bag. Hea y duty black nylon bag
with red trim and white logo. DTXP2000
DuraTrax Bod Repair Tape
Need a quick, easy fix for Lexan®body damage?
When used with Shoe Goo II fixit compound
(DTXC2460), the tape's open wea e, nylon
mesh design offers enough flexibility to pre ent
future cracking. DTXR1210
DuraTrax Bearing Completer Set
Reduce friction, drag and extend the life of
your Maximum MT's parts with this ball
bearing set. Includes all sizes needed to
replace the bushings included with your
Maximum MT. DTXC2541
DuraTrax Kwik-Pit™ 500cc Fuel Bottle
Fast, clean pit stops are as close as the Kwik-Pit
Fuel Bottle. The long, angled neck reaches
easily into your tank to pre ent fuel spills, the
clear plastic body keeps the fuel le el in plain
sight and mo ing fuel from the bottle to your tank
takes just a gentle squeeze. DTXP0150
DuraTrax 4-Shoe Clutch Kit
Tweak your Maximum MT for amazing
acceleration! This kit increases surface area
compared to 3-shoe clutch designs for an
impro ed clutch bell grip. Requires bearings
(DTXC1535) and clutch bells (DTXC2521-
DTXC2526). DTXC2541