Primal RC 1/5 Mega Truck User manual

1/5th MEGA TRUCK
Table of Contents
2
2
3
3
4
5
5
6
7
8
8
9
9
10
11
Differential
Front Axle 15-19
Rear Axle 20-22
Transmission 22-26
Engine
Chassis
Fuel Tank
Receiver Box
Main Sway Bar
Linkage
Axle
26-28
29-33
34
35-36
37
38
39
Shock 40-42
Sway Bar Link 42-44
Tire 44-45
Roll Cage
Body
Parts List
45-50
51-52
53
Pg.
Instruction Videos Available at
PrimalRC.com/Video/TruckInstructions
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Safety Guidelines
Terms of Use
Safety is Your Responsibility
Gas Engine Use Warning
Assembly Instructions
Wiring Diagram
Remote Engine Killswitch & Fail-Safe
Radio Details
Before You Drive
Running Your Truck
After you Drive
Choke Removal Instructions
Steering Servo Saver Adjustments
Brake Adjustments
Transmission Gears Adjustment
Troubleshooting Guide
Assembly
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12-13
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1/5th MEGA TRUCK
Thank you for purchasing the Primal RC 1/5 Scale Mega Truck.
This manual contains the instructions you need to operate and maintain your truck. It is very important that you take the time to read and
understand the instructions and radio manual. Make sure you read and follow the precautions and warnings in the Safety Guidelines
section. These guidelines will educate you on how to run your truck safely and maximize its longevity and performance.
This truck requires advanced R/C user experience and expertise. You must be 18 years of age or older to operate this vehicle. Even if you
are an experienced R/C driver, it is important to read and follow the safety guidelines in this manual.
If you have any questions regarding this vehicle or this manual: Stop. Do not use this vehicle and contact us at
[email protected].
Thank you again for your purchase and we look forward to exceeding your expectations.
Safety Guidelines
WARNING – RISK OF FIRE, INJURY OR DEATH
The truck is not a toy. The truck requires an advanced set of skills and is not intended for use by children or minors under the age of 18.
The truck is intended to be purchased and operated by competent, adult R/C users possessing qualified skills and experienced driving
ability. The user of this vehicle should be practical, mature, intelligent and display good common sense.
Caution must be taken to ensure the safety of yourself and others around you. This truck is very large and is capable of high speed and
quick acceleration. Collisions of a critical nature (injury, death, severe property damage) can result if the truck is operated in a careless or
unsafe manner. Always take great care to make sure all systems are working properly before operation.
The user must be aware of their limits and abilities. Make certain to have adequate space where the truck can be run safely.
The truck requires the use of 2-stroke gasoline for its engine. Gas engines and 2-stroke gasoline have a very high risk of fire and injury if
they are handled improperly. The truck comes equipped with a NI-MH receiver battery. Please read and understand the proper procedures
for charging the battery.
The user must read and understand all the included instructions regarding the proper operation, maintenance and safety precautions in
using a 2-cycle gas engine and charging batteries.
Terms of Use
This product is sold by Primal RC with the understanding that the buyer accepts full responsibility for all actions associated with its use.
Serious injury, property damage, or death can result from driving the monster truck or using any of the included accessories in an unsafe or
irresponsible way. The buyer assumes all liability with this product including any actions that occur due to a failure to follow its safety and
operating instructions resulting in unsafe or improper use or any action that violates the pertinent laws and regulations. Primal RC, and all
the Primal RC dealers, will not be held accountable under any circumstances with the use of this product resulting in property damage,
personal injury, or death. This includes any willful or unintentional damages that may arise out of the assembly or use of the product or its
accessories. The user accepts all liability by the act of using and operating the truck and releases Primal RC, and all Primal RC dealers of
any and all liability associated with its use. Primal RC requests that you do not use this product if you as a user do not accept liability of
ownership. If you don’t accept liability, please do not open any of the enclosed accessories, do not attempt to start it, and contact us to
make arrangements to return the product. Used vehicles cannot be accepted for returns or exchanges under any circumstances. The
material included in this manual can be changed without notice. Primal RC reserves the right to make improvements to the products with no
commitment to integrate those improvements into products sold previously. The manual is subject to change at the discretion of
Primal RC. For the latest version of the manual please visit www.PrimalRC.com.
If you have any questions regarding this Terms of Use, stop and do not go any further. Do not run your vehicle and contact Primal RC at
[email protected].
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1/5th MEGA TRUCK
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•
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•
•
•
•
•
•
•
•
•
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Safety is Your Responsibility
Your radio system may be subject to radio interference from many sources that are out of your control. Please be aware that
radio interference may cause a temporary loss of control. Allow adequate space in all directions when running your truck to
prevent collisions if radio interference should occur.
Test the range of your transmitter in the area you are driving. Make sure not to drive too far and go out of range.
After testing the range, start by driving slowly in the area to make sure there is no interference that can cause temporary
losses of control.
Always test the failsafe system every time before use to ensure it’s working properly (instructions are in the radio manual).
Use new or freshly charged batteries in order to boost signal output power and range.
The motor and exhaust become hot during use. Be careful not to touch them while hot to avoid getting burned.
Remember: SAFETY FIRST. Create a safe environment to run the truck and use good common sense. This will ensure
maximal enjoyment while using the truck.
Avoid making changes not shown or suggested in the instruction manual. You can cause damage to the model and injury to
yourself or others if the product is altered in a way not intended.
Do not pick up the truck by its wheels or tires. Keep your hands free and clear of any moving parts when the electronics are
turned on. Gravel, dirt, sticks, and other debris can be kicked up from the rear wheels during aggressive starts. Avoid standing
directly behind the truck and make sure other watchers are at a safe distance to avoid being hit. Eye protection is always
recommended.
Be sure to check over the truck after each driving session. Check for damage or any loose parts and correct any issues right
away before using again. Make sure to check and tighten the wheel nuts before each session.
Don’t drive the model too close to you, other persons, or property where collisions may occur. Allow a comfortable amount of
space to maneuver the truck.
Always have a clear view of the model when driving. Do not drive at night or when your vision may be blocked in any way.
Try to always bring a friend while driving. Another set of eyes is helpful to identify potential hazards such as an animal or person
crossing in the driving path.
Drive in the proper area. This product is not designed to be used in heavy traffic areas where its operation would cause
pedestrian and vehicle interruptions. This is recommended to prevent collisions causing property damage, injury, or death.
Gas Engine Use Warning
A mixture of gasoline and 2-stroke oil is used for fuel. Please use caution when handling fuel.
Keep fuel away from open flames, heating sources, direct sunlight, smoke, batteries or any ignition source. Store fuel in a well-ventilated area.
Store fuel and truck in a location children can’t access.
Keep fuel and truck away from children.
Gasoline is flammable, toxic, and can produce noxious vapors. The exhaust emitted from the truck can also produce noxious vapors. These
vapors can irritate eyes, respiration, and be dangerous to your health. Always operate the truck in a well-ventilated area.
The 2-cycle engine that comes on this truck only uses a mix of gasoline and 2-stroke oil. The oil/gas mix is how the engine is lubricated. Never
run straight gas through the engine as catastrophic damage may result. Never use glow fuels intended for R/C car use.
WARNING – FIRE RISK: EMPTY THE FUEL TANK BEFORE STORING THE TRUCK.
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1/5th MEGA TRUCK
Assembly Instructions
This truck is shipped in two boxes. One box contains the main chassis with body installed, sticker sheets, two wheels, transmitter,
battery, charger and accessories. The second box contains front and rear axle, brake system, two wheels and four shocks.
Before assembling and starting your truck, read and understand all manuals and familiarize yourself with the truck completely. If you
decide this truck is not the right choice, or you do not want to assume responsibility for your safety, then do not attempt to assemble or
start it. Do not run the vehicle at all and please contact us to make arrangements to return the vehicle.
If your vehicle arrives with damage from transit please do not run the vehicle, and contact us instead. Used vehicles cannot be accepted
for returns or exchanges under any circumstances. If you have any questions about your truck, please email us at [email protected].
Maintenance and replacement parts may be purchased directly from www.PrimalRC.com.
If you are prepared to assemble the truck, visit our website and view the installation videos.
See instruction video on www.PrimalRC.com/Video/TruckInstructions
Then follow along the instructions provided below. If you do not feel comfortable completing the assembly below. STOP. Do not use the
truck. Contact us and we can discuss the concerns with you on the phone or by email.
This truck is intended for users that have extensive experience with gas R/C vehicles and 2-Stroke engines.
1. Position main frame and axles on a surface with enough clearance for assembly.
2. Install the brake rotor on the driveshaft and install the drive shaft pin through the drive shaft and pinion gear shaft.
3. Slide the drive shaft from the axle into the drive shaft coming out of the transmission. Make sure the brake rotor is
installed on the axle.
4. Attach the axle to the four links already assembled on the main chassis.
5. Install shocks on the main chassis and axles. Note: hardware is already installed on axles and chassis.
6. Connect the two servo wires to the wires coming out of the receiver box. There is no preference for left or right
servos –either servo can go into either plug.
7. Attach top sway bar links to already installed sway bar on the chassis. Then attach lower sway bar links to the axle.
8. Install the brake calipers with one pad on each side of rotor (see diagram assembly instructions #66).
Note: The two bolts that hold the brake pads to the caliper should be installed using RED lock tight at the right position.
Without lock tight, these screws will come undone very easily.
10. Install the brake cables (see diagram assembly instructions #66). Make sure to route cables as smoothly as
possible for ease of operation. Cables should not be bent sharply. Zip-tie cable in strategic location to avoid snagging
during operation. Ensure suspension can travel smoothly without pulling on brake cable. See instruction video on
www.primalrc.com/video/TruckInstructions.
11. Initial brake cable adjustment: First, ensure your throttle servo is working properly and giving full throttle to
carburetor. Then in neutral (i.e. your throttle is not being applied) slide the brake cables into the brake servo cable
splitter. Adjust the stop collars so that the breaks are about to apply as soon as you trigger the transmitter to brake
position. This adjustment is something that you will fine tune to your needs. Front and rear bias can also be adjusted at
the same time.
See instruction video on www.PrimalRC.com/Video/TruckInstructions.
12. Install wheels using supplied lug wrench. The hex nuts have a serrated side, ensure it is facing the rim.
13. Remove protective body film, then install stickers on the body. Painted bodies may already have the film removed.
See instruction video on www.PrimalRC.com/Video/TruckInstructions.
14. Charge the battery with included charger.
15. Install batteries into transmitter.
16. Follow the instructions in the “Before You Drive”, “Running Your Truck” and “After You Drive” sections of this manual.
Note: Looking at the pictures of the truck on our website can guide you to ensure that you are assembling the truck correctly. Also
viewing the instruction videos will give you tips on how to install everything correctly and easily.
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1/5th MEGA TRUCK
Wiring Diagram
Features
Setup
LED Explanation Engine status
Correct Can start
Cut-off
Cut-off
Low Battery Voltage or no signal
CH3(AUX) is on
Green
Red
Red Blinking
CH1: Steering
CH2: Throttle/Brake
CH3: Engine Breaker
CH4: Reverse servo
CH5: AUX
CH6: AUX
CH1
CH1
CH2
CH4
CH4
Switch
Switch
T plug
To 2S Li-Po battery To receiver CH1
To Y-link
To receiver CH4
To receiver BATT.
When use extra battery for the receiver,
please pull out the Positive pin (Red).
VCC
Steering servo 1
Steering servo 2
Throttle servo
Brake servo
Reverse servo
S
+
-
S
+
-
S
+
-
_
+
S
_
+
S
_
+
S
Receiver
_
+
S
_
+
S
_
+
S
CH2 Y-link
To Engine Switch
CH3 S
Engine Breaker
Reverse switch
Bind/VCC
_
+
S
_
+
S
_
+
S
_
+
S
_
+
S
Voltage display
REMOTE ENGINE KILL-SWITCH & FAIL SAFE
1. If receiver loses signal, the RED LED will light and engine will cut off. The fail safe will also engage the brakes to stop the vehicle.
2. The engine can manually be cut off by CH3(AUX) from the transmitter. The RED LED will flash.
3. If low battery voltage is detected the RED LED will light and engine will cut off.
DON'T start the engine yet!
Hold the throttle trigger fully to the brake position and set the brake end point adjustment (EPA) to 100%. The RED LED should light signaling an engine
cut-off. If the LED doesn't light, toggle the REVERSE SWITCH and try again. As you setup the receiver's Fail-Safe function, push the throttle trigger to full
brake. Once the Fail-Safe function is setup, return the EPA to its original setting. To verify the Fail-Safe function has been correctly set, turn off the
transmitter. The RED LED should turn on.
If everything is setup and connected correctly the GREEN LED will light up and you're ready start the engine.
The engine can be manually cut-off at any time by pressing the CH3(AUX) button. The RED LED will blink red when successful.
LED Status Display
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1/5th MEGA TRUCK
Radio Details
Bind/VCC
LED
Antenna CH 1-6
Receiver
Battery
Compartment
Button
(Channel 3)
Throttle/Brake
(Channel 2)
Steering
D/R
Power Switch
BACK/Exit
BIND
LED Indicator
LCD
Channel 5
NaviKey
(Rotate to “Select”, press to
“Confirm”)
3 Position Switch
(Channel 4)
Steering Trim
(Channel 1)
Throttle Trim
(Channel 2)
Steering Wheel
(Channel 1)
Channel 6
Antenna
Transmitter
The transmitter and receiver have been pre-bound before delivery.
If you are using another transmitter or receiver. follow the steps below to bind the
transmitter and receiver:
1. Connect the bind cable to the receiver’s B/VCC port.
2. Connect power to any other port.
3. Press and hold the transmitter’s bind key and turn on the transmitter at the same time.
4. Once binding is complete the transmitter will exit bind mode. Remove the power and
bind cable from the receiver then apply power to the B/VCC port.
5. Check to make sure everything functions as expected. If not repeat the steps above.
Binding setup
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1/5th MEGA TRUCK
Before You Drive
It is extremely important that you read, understand, and follow all instructions in the manuals included with this truck
in order to prevent serious damage to your truck, yourself, and your property. If the user fails to follow these
instructions, it will be considered negligence.
Before assembling and starting your truck, read and understand all manuals and familiarize yourself with the truck completely.
If you decide this truck is not the right choice, or you do not want to assume responsibility for your safety, then do not attempt
to start it. Do not run the vehicle at all and please contact us to make arrangements to return your vehicle.
Used vehicles cannot be accepted for returns or exchanges under any circumstances. If you have any questions about your
truck, please email us at [email protected]. Maintenance and replacement parts may be purchased directly from
www.PrimalRC.com.
Follow these steps before each drive session:
1. Mix Gas and 2-Stroke Oil
• Pump gasoline – 87 octane or higher – ethanol-free gas is highly recommended
• 2-stroke oil. Amsoil or Klotz (recommended): Mix 25:1 ratio (gas/oil)
2. Check to make sure you have a fully charged receiver/servo battery in truck. To access battery remove 4 bolts holding the
battery box cover on.
3. Check to make sure your transmitter batteries are good.
4. Check all servos (Steering, Throttle, Brake, Reverse).
•DON’T start your vehicle’s engine yet!
• Turn your transmitter on.
• Turn the truck’s battery switch on (the large red switch located on the battery box; the small black switch is for the
voltmeter).
• Hold the trigger on the transmitter into full brake position. Confirm that the brakes prevent the truck from moving when you
try to push it. If it rolls easily adjust brakes as described in the Assembly Instructions section above.
• Test left and right steering servos by lifting the front of the truck and moving the servos via the transmitter. Ensure the
servos are moving smoothly and there is no excessive play or binding. Adjust servo end points so that the servo is not
pushing the steering linkage far enough to touch the servo mounts.
• Test throttle servo by giving full throttle and ensure carburetor is moving to full throttle position.
5. Check Remote Engine Kill Switch:
•DON’T start your vehicle’s engine yet!
• Make sure the Manual Engine switch is ON (located on frame under front right wheel well).
• The Remote Engine Kill switch system is located inside the battery box and has an LED light. It is visible through the
battery box window. The light is GREEN when it is ready to start and run. If the light is RED this means the Remote Kill
switch is on and your engine will not start. Your transmitter’s third channel button operates the Remote Kill switch.
• To test the Remote Kill switch, press the third channel button on the transmitter. The light should turn RED. Press it again
to change it back to GREEN before you run the truck.
6. Check the Radio Fail Safe: The radio system that comes with the truck has a fail safe automatically installed ensuring that if
your transmitter’s signal is not reaching your truck’s receiver the brakes will be applied automatically. To test:
•DON’T start your vehicle’s engine yet!
• Turn your transmitter on.
• Turn the truck’s battery switch on (located in the back on the battery box).
• Turn your transmitter off.
• Your brake servo should now apply the brake on its own.
• You have now confirmed that the failsafe is working. Should the receiver lose signal from the transmitter, the brake will
automatically be applied.
• Turn your transmitter back on for normal use.
7. Go over truck to make sure there are no loose screws.
8. Check lug nuts by tightening with provided wrench. Ensure the serrated side of hex nut is facing the rim.
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1/5th MEGA TRUCK
Running Your Truck
1. Add 2-Stroke gas and oil mix to gas tank.
2. Turn your transmitter on.
3. Turn the truck’s battery switch on (located in the back of roll cage).
4. Make sure your Manual Engine switch is set to the ON position (located on frame under front right wheel well).
5. Move choke lever to full choke position.
6. Push primer bulb several times, until you see gas going through carburetor and back into gas tank lines.
7. Pull start the engine with a steady, smooth, quick pull until you hear the first pop of the engine trying to start. This is an easy pull start
system. There is no need for aggressive, quick pulls. Do not over-extend the pull-start or your pull starter may become damaged.
8. Flip the choke lever to off position (down). Make sure it stays in position (see page 13).
9. Pull start the engine again with short, quick pulls until your engine starts.
Sometimes a little throttle input from the transmitter may be necessary to start the engine.
Be careful to not give too much gas – it may result in the engine flooding.
10. If you are running the truck for the first time, engine break-in is recommended.
The engine break-in process alternates heating and cooling the engine to allow all parts of engine to properly seat themselves. It also
allows 2-stroke oil from the incoming fuel to coat the interior parts of the engine.
Run the engine at varying speeds for periods of 3 to 10 minutes at a time. During this break-in process, never go full
throttle.
Try to stay below half throttle. Always let the engine idle for 30 seconds before turning it off. Allow the engine to cool off for 10 minutes
before starting it again. Repeat this process 3 or 4 times (3 or 4 full heat cycles).
11. Reverse Driving Instructions
To drive the truck in reverse, ensure that the truck has come to a complete stop, then switch channel 4 from the transmitter. Switch to
the opposite position – it's a 3-position switch, so be sure to toggle between the furthest positions. This will cause the servo to active the
reverse function in the transmission. Test this by giving it a little gas to confirm that reverse is engaged. You may need to toggle the
switch ON and OFF again to engage if reverse is not working.
To go back to forward driving repeat the process of bringing the truck to a stop and then switching channel 4 to the opposite position.
Note: Because of the size and weight of the truck, try to avoid steering the truck while it is not moving. This will extend the life of your
steering servos.
Note: This truck is not waterproof. Do not submerge this truck in deep water. Small puddles or shallow water should not be a problem.
Note: If you are planning on driving this truck in excessive dirt, we recommend that you remove the installed choke.
Follow the Choke Removal Instructions in this manual. It might be more difficult to start the truck without the choke, however, your engine
will last longer because this choke system can let dirt into your engine.
Note: Using a 2S LiPo battery is possible and will provide better steering and braking power.
After You Drive
• Be sure to let the engine idle for 30 seconds to cool before stopping the engine.
• Press the Kill Switch button (channel 3) on your transmitter to shut the engine off.
• Turn battery switch OFF (located in the back of roll cage).
• Turn your transmitter OFF.
VERY IMPORTANT: ALWAYS turn off the truck first, then the receiver, then the transmitter in that order. If your receiver or battery switch is left ON and
your transmitter is OFF the failsafe will cause the servos to overheat and eventually burn out.
• If your truck is wet or dirty, we recommend rinsing the dirt off with a gentle stream of water and then using compressed air to dry it off.
•Important! Lubricate joint areas and moving parts with WD40 to prevent rust and keep truck working properly for many years to come.
(example: wheel bearings, suspension links, drive shafts, servo cables)
• Inspect the truck for loose screws, broken and missing parts. We recommend blue lock-tight for screws that are threaded into aluminum
parts that do not have nylon lock nuts.
• If you are storing your truck for a month or more, we recommend draining the gas out of the tank and carburetor.
Love your truck by taking good care of it and it will love you back.
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1/5th MEGA TRUCK
Choke Removal Instructions (optional)
• Watch the instruction video at www.PrimalRC.com/Video/TruckInstructions.
•Loosen air filter clamp and slide air filter off.
•Remove the two screws that are holding the choke system onto the carburetor. To prevent the carburetor from
falling off while you remove the screws, hold the carburetor in place.
•Remove the choke plate and lever system and reinstall the velocity stack directly onto the carburetor using the
same two screws that you removed earlier, but install 2 additional lock washers on each bolt to act as spacers
and allow for proper tightening.
•Reinstall the air filter and tighten the clamp.
Steering Servo Saver Adjustments
The steering system has both servos linked to an adjustable centralized servo saver system. This system helps
keep the servos from being damaged when force is put on the front wheels. You can adjust the sensitivity of the
system by loosening or tightening the large hex nut on the servo saver spring. Tightening the spring will allow
more control of the steering, however the servos will be more vulnerable to damage upon impact. Loosening the
spring will reduce steering control, but offer more protection for the servos. Finding the optimal ratio is a matter of
personal preference, so test different settings to find one that you prefer.
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1/5th MEGA TRUCK
Brake Adjustments
Watch the instruction video at www.PrimalRC.com/Video/TruckInstructions.
Because the brake system is on the drive shafts, this truck can stop very quickly. If your truck is not stopping
quickly brake adjustment is necessary.
This may include changing brake pads and/or rotors, adjusting brake cable tension, and adjusting servo end
points. We recommend that you watch our detailed videos online to learn how to adjust your brakes.
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1/5th MEGA TRUCK
Transmission Gears Adjustment
The truck uses a single-speed transmission that has five different gear ratios to choose from. The mid-range gear set is
installed in the truck out-of-the-box (spur/pinion ratio 25:25). Other gear sets that are included with your truck change the
driving and power experience. For crawling, we recommend switching to 20:30 or 23:27 ratio. We recommend 27:23 and
30:20 for optional high-performance engines with greater speeds.
The installed ratio (25:25) is a good overall gear set that we recommend for common use.
To change the gearing in the transmission: (See diagrams #24 and #25 in this instruction manual)
• Remove the rear drive shaft from the rear output shaft of the transmission (a 4mm hex pin holds it in place).
• Remove the six screws (4mm hex) from the transmission case.
• Remove transmission cover and the two ball bearings that hold the gears on.
• Slide off the two gears and install the gear set with your preferred ratio (pinion gear on the left, spur gear on the right
which is also the transmission output shaft)
Note: Ensure that the gears are greased. You can use the grease that is already in the transmission. Note: The
smaller the pinion gear, the slower the truck will drive, but the more low-speed power it will have.
• Reinstall the two bearings, the cover and the rear drive shaft to their original positions.
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1/5th MEGA TRUCK
Troubleshooting Guide
The engine doesn’t start or is not running well
o Make sure your gas and oil are mixed properly.
Mix Gas and 2-Stroke Oil
• Pump gasoline – 87 octane or higher – ethanol-free gas is highly recommended
• 2-stroke oil. Amsoil Saber (recommended)
• Mixed 25:1 ratio (gas/oil)
o Follow the instructions in this manual for “Running Your Truck”. If your truck still does not start, try the following:
• Check to make sure your spark plug is clean and working. Remove the plug from the engine and inspect the tip. If it is
clogged, it will need to be cleaned or replaced. After the plug is removed, check if the plug is working by:
o Attaching the wire to the top of the plug
o Placing the tip of the plug very close to the metal of the cylinder.
o Pull the pull start a few times. A spark should jump from the plug to the cylinder
o If no spark or a weak spark is observed, replace the plug. Ensure the plug is properly gapped (0.028" or 0.7mm).
Ensure the ignition coil and flywheel are properly gapped (flywheel gap should be about the thickness of a
business card), then check again.
o If still no spark - you likely have a problem with the ignition coil and will need to replace it.
• The Remote Kill Switch may not be working properly and will need to be tested.
• Check to make sure your carburetor is properly tuned. You may need to adjust the screw slightly in either direction to
find correct tuning for your carb.
• Your engine may be flooded. This can happen if you have pushed the primer bulb many times, or pulled the pull start a
lot of times.
o Remove the spark plug and allow all the fuel in the cylinder to evaporate.
• Your compression may be bad. If you have an older engine, the piston rings may need replacement.
• Check your carb gasket, intake gasket, cylinder gasket, and crankcase gasket. Can you hear air whooshing out of the
cylinder gasket or crankcase gasket when you pull the starter? Is air leaking in the manifold gasket behind the carb?
o A gasket leak results in a loss of compression and/or improperly mixed fuel and air. An easy way to check for intake
leaks is to spray the intake manifold and area surrounding it with
WD-40. If the idle changes after you spray the WD-40, there is an intake air leak.
o Common areas for leaks are between the manifold and the cylinder, and between the carb and the intake manifold.
Inspect the manifold, carb gasket, and intake gasket for cracks or other signs of damage, replace if necessary.
• Make sure your gas cap is venting properly. There should be a small hole in the plastic cap and bladder. If it becomes
blocked or clogged it can cause issues. Also check to make sure fuel lines are connected correctly, the fuel lines aren't
cut, and the fuel filter is attached.
• Make sure there is no debris (grass/dirt/etc.) clogging the pull start, air filter or engine. This can result in the engine
running too hot and becoming overheated.
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1/5th MEGA TRUCK
Troubleshooting Guide (continued)
The engine doesn’t idle well
The servos aren’t responding, or the transmitter is not connecting
oIf the idle is too low, turn the carburetor idle screw clockwise to raise idle. If the idle is too high turn it
counterclockwise until the desired idle is reached. Idling as low as possible is recommended without the
engine stalling. The clutch may start to engage, preventing the reverse function from working properly.
oCheck that transmitter switch is on
oCheck that truck’s battery switch is on
oCheck the wire connections. Make sure they're intact, connected properly, and the polarity is not reversed (see wiring
diagram on page 5). Make sure to line tabs up: black to black and red to red.
oCheck that your batteries are charged
oCheck to make sure your transmitter and receiver are bound.
oVery Important: Setup all settings in the radio, especially the end point adjustments. Maxing out your end point
adjustments can place too much stress on the servos and burn them out prematurely. The radio manual has
explanations on how to setup and adjust all functions.
oIf you suspect a servo has gone bad you can test it by plugging it into a known working receiver port.
For instance: If the steering servo is not responding, but the throttle servo is working, plug the steering servo
into the throttle servo's receiver port and test it. If the steering servo works in the new port the problem is not
the servo.
oThe most common reason for servo failure is overload. Steering the servo while the truck is stationary too often can
overload the servos and burn them out.
oIf you suspect one of the steering servos has failed, stop and turn off the truck. Prolonged use while one steering
servo is not working may overload the other steering servo.
oIf you notice decreased response time on the servos you may need to charge or swap out the battery.
The servos aren’t moving in correct direction
oCheck servo reverse functions on the transmitter.
The brakes are not working, but the brake servos are moving
Reverse is not working
oAdjust cable wire to ensure that the brake is pulling properly on the calipers.
oCheck to make sure brake pads are not worn out.
oCheck that drive line axle pins and driveshaft pins are not broken.
oMake sure you stop the truck from rolling before switching to reverse.
oCheck that your idle is low. If idle is too high, The clutch may start to engage, preventing the reverse function from
working properly.
oAdjust the reverse servo cable to ensure that it is pulling enough to engage reverse properly.
Choke lever is not working
oIf the choke lever is not staying in position you may need to bend it at about a 30° angle. This will enable it to stay in
position better.
13

1/5th MEGA TRUCK
1
Diff Oil
#20000cst
×2
Differential Assembly
MBS4010 MBS4010
MBS4010
×4
M4×10mm
MFS4012
RMT108
RMT145
RMT108
RMT035
RMT157
RMT157
RMT086
RMT108
RMT108 RMT108
RMT108
RMT106
RMT107
RMT107
RMT107 RMT107
RMT107
RMT107
MFS4012
MFS4012
×8
M4×12mm
BBS101504
BBS101504
BBS101504
BBS101504
BBS101504
Bearing 10×15×4mm ×8
BBS203207
BBS203207
BBS203207
Bearing 20×32×7mm ×4
ORS14020
ORS14020
ORS14020
O-Ring D14×2mm ×4
ALWAYS
USE
14

1/5th MEGA TRUCK
2
3
4
Front Axle Assembly
MCS4020 ×2
M4×20mm
MCS5040
M5×40mm ×7
×6
MCS5014
M5×14mm
MCS5016
MCS5016
MCS5016
MCS5020
MCS5020
×8
×10
M5×16mm
M5×20mm
MFS6016
MFS6016
MFS6016
×8
M6×16mm
L/R
BBS102206
BBS102206
Bearing 10×22×6mm ×2
BBS122406
BBS122406
BBS122406
BBS122406
Bearing 12×24×6mm ×4
ALWAYS
USE
ALWAYS
USE
ALWAYS
USE
Notice the direction
of the differential
×2
RMT085
RMT001
RMT001
RMT002
RMT006
RMT003
RMT003
RMT007
RMT007
RMT002
MCS5040
MCS4020
MCS5014
MCS5014
MCS5014
MCS5020
MCS5020
15

1/5th MEGA TRUCK
5
6
L/R
×2
MCS6020
MBS6020
×4
M6×20mm
MCS5010
MCS5010
×2
M5×10mm
PINS5024
PINS5024
×2
M5×24mm
MCS5016
MCS5016
×1
M5×16mm
MCS5016
MCS5016
M5×16mm ×2
BBS101504
BBS101504
BBS101504
Bearing 10×15×4mm ×2
ORS22025
ORS22025
O-Ring D22×2.5mm ×1
BBS122406
BBS122406
Bearing 12×24×6mm ×2
BBS203207
BBS203207
Bearing 20×32×7mm ×2
ALWAYS
USE
ALWAYS
USE
RMT019
RMT004
RMT052
RMT044
RMT044
RMT044
RMT041
RMT039
RMT009
RMT138
RMT009
RMT039
RMT016
RMT046
MWS202810
1 mm
MCS6020
MCS6020
×2
M6×20mm
MBS6020
16

1/5th MEGA TRUCK
7
8
9
MFS3014 MFS3014
MFS3014
PRE005
PRE005
MFS3014
MFS3014
×8
M3×14mm
MCS4012
RMT015 RMT015
RMT015
RMT015
MCS4012
×4
M4×12mm
MCS6016
MCS6016
×2
M6×16mm
MFS5016
MFS5016
MFS5016
×4
M5×16mm
MBS4012 ×2
M4×12mm
MBS6040 ×1
M6×40mm
MCS3008 ×2
M3×8mm
MCS3012 ×2
M3×12mm
ALWAYS
USE
ALWAYS
USE
ALWAYS
USE
MCS6016
MCS4012
MWS030810
Washer 3×8×1mm ×8
RMT044
RMT103
RMT103
RMT042
RMT017
RMT018
RMT018
MBS4012
MBS4012
MBS6040
MCS3008
MWS030810
MWS030810
MCS3008
MCS3012
MCS3012
17

1/5th MEGA TRUCK
10
11
12
159 mm
99 mm
80 mm
20 mm
L/R
MNNS60
MNNS60 MNNS60
MNRS60
MNRS60
MNRS60
M6 Nut
M6 Reverse Nut
×4
×4
MFS6020
MFS6020
MFS6025
MFS6025
MFS6025
MFS6025
×2
×6
M6×20mm
M6×25mm
MCS5012
MCS5012
MCS5016
MCS5016
MCS5016
×1
×4
M5×12mm
M5×16mm
ALWAYS
USE
ALWAYS
USE
ALWAYS
USE
×2 ×2
RMT110
RMT080
RMT038
RMT080
RMT080
RMT050
RMT049
RMT110
RMT111
RMT111
18

1/5th MEGA TRUCK
13
14
15
RMT055 ×1
M8×27mm
MFS3010
MFS3010
×4
M3×10mm
MSS4004
MSS4004
×2
M4×4mm
BBS050825
BBS050825
BBS050825
Bearing 5×8×2.5mm ×4
MES40
MES40
E-clip 4mm ×2
MCS3020
MCS3020
MCS3020
×4
M3×20mm
MCS3020
MCS3020
×2
M3×20mm
×2
ALWAYS
USE
ALWAYS
USE
ALWAYS
USE
RMT036
RMT055
RMT095
RMT099
RMT099
RMT095
RMT096
RMT096
RMT097
RMT034
RMT097
RMT054
19

1/5th MEGA TRUCK
16
17
18
Rear Axle Assembly
MCS4020 ×2
M4×20mm
MCS5040
M5×40mm ×7
×6
M5×20mm
MCS5014 ×6
M5×14mm
MFS6016
MFS6016
MFS6016
MFS6016
MFS6016
×8
M6×16mm
BBS102206
Bearing 10×22×6mm ×2
BBS122406
Bearing 12×24×6mm ×2
ALWAYS
USE
ALWAYS
USE
ALWAYS
USE
MCS6010
×2
M6×10mm
Notice the direction
of the differential
BBS102206
RMT085
RMT001
RMT001
MCS5040
MCS4020
BBS122406
BBS122406
RMT002
RMT008
RMT008
RMT002
MCS5014
MCS5014
MCS5014
MCS5020
RMT006
RMT006
MCS5020
MCS5020
MCS6010
MCS6010
20