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B
ED IE NU NG SA NL EI TU NG
VERS ION 01/0 7
O
PE RAT IN G INS TRUCTIONS
VERS ION 01/0 7
N
OT IC E D´UTI LI SATION
VERS ION 01/0 7
G
EB RUI KSAANWIJZING
VERS IE 01/07
PREDATOR PRO RTR
4WD MONSTER TRUCK
Nr. 23 31 87
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
Thank you for purchasing a RC car by CONRAD Electronic.
The car model you have purchased has been manufactured using state-of-the-art technology.
The product meets the requirements of the current European and national guidelines on electromagnetic compatibility.
EC Conformity has been proven and the relevant statements and documents have been deposited at the manufacturer.
We reserve the rights to effect modifications to the technology and the design without prior notice.
All company names and product designations contained herein are trademarks of the respective owners.
All rights are reserved.
Warranty
Unless otherwise stipulated in the law, the warranty is limited to repairs up to the amount of the purchase price, the
replacement of the model through an equivalent one or to the return of the purchase price.
Normal wear and tear in operation is excluded from the warranty, as well as damages which were caused by collisions with
hard obstacles or with other vehicles.
In case of damages which are caused due to failure to observe these operating instructions or failure to observe maintenance and equipment specifications, the warranty will expire!
We neither assume liability for consequential damages!
Always observe the safety instructions!
The model is only designed for use outdoors, not indoors.
In order to ensure safe operation, you must, as user, observe these operating instructions.
The car is not suitable for children under 14 years of age, unless under the supervision of adults.
For a fast response of your technical enquiries please contact or consult our Technical Advisory Service:
DEAR CUSTOMER,
This operating manual belongs to this product.
It contains important information about operation and handling.
Please take this into consideration when you pass the product on to third parties.
Keep this manual for future reference!
Take note in the following section of the identification markings:
NOTE! Danger warning, danger to persons or material damages
NOTE! Important note
Note
Tel. +499604 / 40 88 80
Fax +499604 / 40 88 48
E-mail: tkb@conrad.de
Mon to Thurs 8.00am to 4.30pm
Fri 8.00am to 2.00pm
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© REELY 01/0 7
TABLE OF CONTENTS
PREDATOR PRO RTR
4WD MONSTER TRUCK CHASSIS
SCALE 1/10
Item No. 23 31 87
Page
1 SAFETY MEASURES 32
2 DESCRIPTION OF THE MODEL 34
3 PREPARATION 39
3.1 Content of delivery / necessary accessories 39
3.2 Tools and auxiliaries, Check list 40
3.3 Checking alignment and tooth backlash of drive 40
3.4 Putting the RC system into operation 41
3.5 Checking the function of the servos 42
3.6 Checking the range of the remote control transmitter 43
3.7 Checking basic settings of carburettor 44
3.8 Recommendations for operation 45
3.9 Starting the engine 45
3.10 Running-in regulations for the engine 47
4 DRIVE OPERATION 48
5 TUNING 49
5.1 Motor fine tuning 49
5.2 Setting the damping 50
5.3 Setting camber inclination 52
5.4 Setting the alignment 52
6 MAINTENANCE 53
7 TECHNICAL DATA 54
8 TROUBLE SHOOTING 55
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
1 SAFETY MEASURES
DO NOT TAKE ANY RISKS!
Your own security and that of your environment is solely down to you being responsible when dealing with the model.
- Find out from your insurance company whether you are covered when practicing your hobby.
- Remote controlled models are not a toy!
The car is not suitable for children under 14 years of age, unless under the supervision of adults.
- The model is only designed for use outdoors, not indoors.
DO BE PATIENT!
Bear in mind that the operation of remote controlled model vehicles has to be learned step by step.
Improper operation can cause serious damages to people and property.
BEFORE STARTING:
Check all bolted connections and all wheel nuts.
Make sure that the rechargeable batteries (batteries) of both transmitter and receiver are completely charged.
1. Both control levers in neutral position, 2. Switch on remote control transmitter and 3. Receiver
ENGINE, FUEL:
Also pay attention to the running-in regulations for the engine!
- Use model car fuel for RC cars only!
- Never use gasoline for motorcars!
- Never use gasoline for plane models!
The percentage of oil in fuel for plane models is too low.
Risk of burns! Do not touch engine and manifold during operation!
Let the engine cool down first before removing the car body.
Only drive with attached car body!
- Switch off engine:
Stop the fly wheel on the lower side of the car body when the car is in idle speed.
To that effect, use a piece of cloth, gloves or an appropriate object or
block the exhaust with a cloth or something similar in order to stall the engine.
Or: Cut off the air supply to the carburettor.
The fuel supply should not be disconnected as otherwise the engine could overheat.
It is only when the engine is turned off that you may switch off the receiver, then the transmitter!
Danger to health!
- Store fuel in a locked place and out of reach of children!
- Avoid contact with eyes, mucous membranes and skin; contact a physician immediately if you feel unwell!
The individual ingredients of the model fuel, methanol and nitromethane, are poisonous!
- Avoid spilling fuel!
- Use a special fuel bottle to fuel the car.
- Test runs only outdoors!
- Don’t breath in fuel vapors and exhaust fumes!
Ensure sufficient ventilation when fueling the car in closed rooms!
- Check the tightness of hose connections and tank lid before each use.
Risk of explosion! Fire danger!
Car fuel is highly flammable. When fuelling the car, do not smoke; no open fires!
Stock fuel in well ventilated rooms, away from ignition sources.
- Only transport the model with an empty tank!
Empty the tank if you do not want to drive the mode for several days.
- Use appropriate containers for transporting the fuel.
The fuel can eat away and damage varnish and rubber parts.
- Empty fuel containers as well as fuel wastage are a hazardous waste and must be recycled accordingly.
- Do not burn fuel containers!
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DRIVE MODE:
Never drive if your ability to respond is limited (e.g. when tired, under medication or under the influence of
alcohol). Incorrect responses can cause serious damages to people and objects.
- Do not drive in the direction of gathered people, persons or animals!
- Always keep visual contact to your model! Do not drive at night.
- Never drive on roads, which are opened to public road traffic!
Take note of possible conditions and regulations for the site.
- Never drive without air filter!
- Check regularly all bolt connections and fasteners, as they may get loosened or detached due to the vibrations
of the engine.
- Avoid long driving in the part-load operational range, since otherwise, engine and clutch (missing air cooling)
will overheat!
- Avoid driving at very low outdoor temperatures.
The synthetic material of the car body loses its elasticity; Therefore, even small collisions may cause chippings and
fractures.
REMOTE CONTROL:
- Before starting, check the range of your remote control system.
- Firmly screw the transmitter antenna and pull it out to its entire length.
An antenna that is not completely pulled out reduces the range of the remote control transmitter.
- Check, on the stationary model, whether the servos respond to the signal of the remote control!
- Check the charge level indicator of your remote control!
Weak or empty rechargeable batteries (batteries) can cause you to lose control over your model.
- Make sure that nobody else is transmitting in the proximity of your frequency!
Interfering signals on the same frequency can make you lose the control over your model.
Also, when using different modulation types (FM, PPM, AM, PCM), the same frequencyshould not be used.
- Do not drive under high voltage power lines or radio masts.
- Do not drive in the case of thunderstorms!
Atmospheric interferences can affect the signals of your remote control transmitter.
- Don’t drive in the rain, through wet grass, water, mud or snow.
The components of your RC system are not waterproof!
- Make sure that the throttle/brake servo is in idle position.
- Always let the remote control and the receiver turned on whilst the engine is running!
- Switching off: 1. switch off the engine, 2. the receiver then the transmitter!
GENERAL INFORMATION:
- Remove the rechargeable batteries of the receiver if you are not using the latter for a longer period of time.
- Never mix rechargeable batteries with dry-cell batteries.
- Never mix full and half full rechargeable batteries /batteries or rechargeable batteries with different
capacities.
Otherwise, the weaker rechargeable batteries / batteries or rechargeable batteries with low capacity can be totally
discharged and can leak.
- Never try to charge dry cell batteries.
This can cause leakage and in the worst case can cause an explosion
- Defective / rechargeable batteries which cannot be recharged any more are a hazardous waste
(recycling sites).
It is forbidden to dispose of them via the household rubbish!
- Take note of the warning notes and the equipment regulations that are specific to the vehicle!
- Only use original spare parts!
- Take note of the separate operating manuals of accessories such as rechargeable batteries and chargers.
- Ensure extra lengths and loose hanging cables with thin cable fasteners!
Ensure, in particular, that lines do not get into moving parts.
1 SAFETY MEASURES
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
2 DESCRIPTION OF THE MODEL
DO YOU WANT EVERYTHING AND IMMEDIATELY?
You made the correct choice with Monster Truck PREDATOR Pro RtR. The engine with starter cord, air filter, manifold
and resonance tube is already mounted, as well as the complete RC system with servos and receiver with ON/OFF
switch. For the receiver and the rechargeable batteries of the receiver, there is a practical box screwed onto the chassis.
A finished car body and a matching decal sheet are included in the delivery; the car body support is also mounted.
However, you still have to charge rechargeable batteries or to insert batteries, to fasten the spark plug, to fill the tank and
to install the car body. Now, you are ready!
Highest quality materials and first-grade workmanship guarantee untroubled driving fun even under tough operating conditions and a long life of the model.
The low degree of maintenance leaves you lots of time to concentrate on driving and to perfect your manner of driving.
Engine:
Monster Truck PREDATOR Pro is driven by an air-cooled 2,76 ccm two stroke engine with 2.15 kW (1,5 PS).
Slide carburettor, manifold and resonance tube are already mounted.
The slide carburettor of a new type made of aluminum and plastic is easily adjustable, hence allowing for a perfect engine
calibration.
The recoil starter cord that is flanged onto the crank case makes it possible to start the engine without other tools.
The engine is operated with environmentally-friendly model fuel based on oil/methanol, the tank with snap closing and integrated tank pump holds 100 ccm.
Drive:
The driving power of the 1,5 PS two stroke engine is transmitted to the differential in the front and rear axle.
All differentials have metal bevel wheels and planet wheels, the axle drive shafts are supported by ball bearings.
Chassis frame:
The mono-wheel suspension on the double transverse control arms as well as the aluminium oil pressure shock absorbers
on aluminium damper plates adjustable with screw rings allow for an optimization of the road holding for all demands.
An adjustable disk brake with a steel brake disk allows for a braking power adaptable to the driving style and the terrain.
The servo saver protects the steering servo in difficult terrain.
With a ground clearance of 55 mm, hardly anything can stop the PREDATOR Pro in the terrain.
Chassis
The bottom support plate made of aluminium and the RC mounting plate of the double-deck chassis ensure a high stability
with small weight.
Tuning
Clamping screws in the upper transverse control arms are used to adjust the camber inclination of the front and rear axles,
the alignment is also effected via clamping screws as well as by resetting the steering links in other linkage points.
With the tunable aluminum oil dampened suspensions you simply “straighten out” ground unevenness.
TECHNICAL INFORMATION
MEASURE AND WEIGHT
Monster Truck Chassis PREDATOR Pro
Total length Wheel base Width Wheel track Height Weight with engine
(as in delivery)
410 mm 270 mm 320 mm 264 mm 230 mm approx. 2200 g
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2 DESCRIPTION OF THE MODEL
Two-channel remote control transmitter
Pistol grip transmitter with steering wheel for steering and traction lever for speed.
Transmitter and receiver crystal are available separately and can be exchanged.
If you wish to drive your model in a competition or together with other models, this feature ensures that no other person
transmits on your frequency, thus causing you to lose control over your model.
Antenna
Transmitter antenna: Emits the signals of the remote control transmitter as radio signals.
Receiver antenna: A simple wire on the receiver in the vehicle, whose length is exactly tuned to the transmission frequency
of the remote control system with which the control signals are optimally received.
Function selector key
This key is for selecting various functions such as dual rate, ABS, linear or exponential control as well as servo reverse for
the corresponding channels.
Charging socket
The ON/OFF switch must be in the “OFF” position before you start charging!
NOTE! Never try to charge dry cell batteries.
LED display
Indicates the on-position of the transmitter.
Limited steering turn (Dual Rate)
The deflection of the steering servo can be adjusted with the buttons in the range of 30% to 100%.
The highest the selected percentage, the highest the sensitivity of the steering to steering signals.
Servo reverse
Changes the rotational direction / driving direction of the corresponding servo.
Steering wheel
The steering wheel is turned in the desired driving direction towards the right and the left.
Throttle/brake lever
The throttle/brake lever is moved towards the front in order to brake and towards the back in order to accelerate.
Transmitter crystal
Frequency giver of the transmitter. A receiver crystal which has been exactly tuned to the transmitter is inserted in the receiver (on the chassis). To change the frequency, both crystals must be exchanged!
Rocker switch trimming throttle/brake
to fine tune the neutral position of throttle/brake servos.
Rocker switch trimming steering
To fine tune the neutral position of the steering servo. The dual rate function should be set to 100% for that.
With max. control travel for the steering turn, fine tuning is simplified.
TWO-CHANNEL REMOTE CONTROL
2.1
Rocker switch
Trimming channel 2
Transmitter crystal
(back side)
Channel selector key
Function selector key
Selector keys
ON/OFF switch
Steering wheel channel 1:
Drive direction
(steering servo)
Throttle/brake lever
Channel 2: throttle/brake
(throttle/brake servo)
LED display (power)
Telescopic antenna
Rocker switch
Trimming channel 1
Multi-functional display
Dual rate channel 2
(throttle/brake servo)
Charging socket
(side)
Dual rate channel 1
(steering servo)
Battery compartment
(bottom side)
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
2 DESCRIPTION OF THE MODEL
2/4 WD
2/4 Wheel Drive driven by 2 or 4 wheels.
ABC assembly
ABC means “Aluminum”, “Brass” and “Chrome”. Aluminum with its small thermal expansion and small weight serves as
material for pistons, the cylinder is made of brass with chrome-plated contact surface.
Air filter
The air filter is made of foam and prevents the penetration of dust and dirt particles through the suction hole into the carburettor and in the engine.
Alignment
Position of the wheel level to the driving direction:
a) Toe-in – Wheels point inwards
b) Toe-out – Wheels point outward
Axle leg
This is where the axle turns. The steering levers are located on the front axle legs.
Bumper
Made of impact resistant synthetic material for excellent damping in case of a frontal crash.
The back bumper is also a practical carrying handle.
Chassis
The “frame” of the vehicle, to be precise, only the bottom support plate.
4WD MONSTER TRUCK CHASSIS
2.2
a b
Driving direction
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Damper plate
The upper end of the shock absorber of an axle right and left is screwed to the damper plate at the front or at the rear.
The shock absorbers are thus somehow interconnected via the damper plate.
Differential
Differential gear. Equalizes the different revolution speeds, e.g. between the wheel on the inside of a bend and the outside of
a bend.
Fuel tank
The fuel tank with snap closing and tank pump contains 125 ccm. The tank is connected, via a hose, at the connection
nipple in the lid, with the resonance exhaust silencer. During operation, the exhaust gas effects an overpressure in the tank,
which improves the fuel supply to the carburettor.
Inclination
Inclination of the wheels as viewed from the front: Positive inclination Negative inclination
Main nozzle needle
Regulates the fuel supply to the carburettor
RC model
“Radio controlled”, to be more precise: “Remote Controlled” Model
Receiver
Receives and “translates” the control signals of the remote control transmitter (direction and intensity) for the servo and the
cruise control. The transmitter crystal which is tuned to the receiver crystal ensures the perfect communication between
transmitter and receiver. Transmitter and receiver crystals are thus tuned to one another, so that signals of parallel transmitters cannot disturb this receiver (this model).
Resonance exhaust silencer
The resonance exhaust silencer serves, on the one side, to absorb sounds, on the other side, to display the optimal output
of the engine.
Servo lever (servo arm)
Lever, disk or cross with 4 control levers which transmit the rotational movement of the servo
motor via steering levers.
Servo
Servo motor whose shaft turns in a limited angle in both directions and carries out mechanically a control function via a lever.
Servo reverse
(at the remote control transmitter) switches the rotational direction / driving direction of the servo
Servo saver
Cushioned additional link between steering servo and steering link. Sudden, hard shocks on the wheels are dampened by
this link and are not transmitted directly in the servo.
Shock absorbers
The shock absorbers consist of four coil springs in whose center respectively one cylinder with one piston and one piston rod
is located. The springs absorb the travel of the axel halves when traveling on uneven roads. Thus, bounding and rebounding
is limited via the pistons located in the center of the coil springs.
The shock absorbers are fastened between the damper plates at the front and the back and the lower transverse links
2 DESCRIPTION OF THE MODEL
Steering servo Steering
Driver Transmitter Receiver Throttle/Brake servo Engine Center differential (4WD)
Rear axle differential
Receiver battery
Front axle differential
Operating Sequence of the control:
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
Slide carburettor
By sliding the “chocking barrel” the air supply to the engine is regulated. At the same time, the conical
needle of a needle valve (idle nozzle needle) is moved; thus, changing the amount of fuel that flows
through the carburettor.
Spindle
The axis onto which the wheel is screwed and around which the wheel turns.
Starter cord
With recoil spring to start the engine manually. It turns the crank shaft and therewith the piston via the piston rod, thus the
engine
Steering knuckle arm
Lever on the axle leg (steering lever). Moving the steering link via this lever towards the right or left causes the wheels to
swivel in.
Steering knuckle pin
Steering axle of the wheel. Connects the axle leg so that it is rotary with the axle leg support (between the top and bottom
transverse control arm).
Steering link
Generally consists of three flexible interconnected levers. The outer steering links (adjustable in length with adjustable
alignment) connect the steering knuckle arm at the axle leg so that it is rotary with the middle steering link part, which is
tilted right / left by the steering servo lever.
Steering link lever (=steering lever)
Lever on the axle leg. Moving the steering link via this lever towards the right or left causes the wheels to swivel in.
Steering servo
Servo-motor, that carries out mechanical control functions via a lever.
This servo effects steering via the steering links. A servo saver integrated in the servo control lever protects the servo from
damages, which can cause strong shocks against the wheels via the steering links at the servo transmission.
Throttle/brake servo
This servo controls the slide carburettor as well as the disk brakes
Throttle stop screw
Regulates the minimum air supply to the carburettor in idle speed
Transverse link
Half axle transverse to the direction of motion, connects the wheel suspension (spindle, axle leg and steering knuckle pin)
with the chassis.
Trim
To fine tune the neutral position of the servo. The trim is superposed by the turns of the remote control lever.
Thus, the neutral position of the servo can be switched in one direction or the other.
2 DESCRIPTION OF THE MODEL
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3 PREPARATION
SCOPE OF DELIVERY
- One Chassis
- 2,76 ccm two stroke glow engine
with 1,1 kW (1,5 PS), with
manifold, resonance tube, air filter and pull starter,
already mounted
- Steering servo, Throttle/brake servo and receiver,
already mounted
- fuel hoses, already laid.
- Four wheels with chrome-plated plastic rims and
already mounted Monster Truck tires
- Monster-Truck car body, imprinted
- Decal sheet
- Splints to fasten car body
- A plastic tube as guidance for the wire aerial
- one two-channel remote control
(pistol grip transmitter)
- these installation and operating instructions
NECESSARY ACCESSORIES
Not included in the delivery
- batteries or rechargeable batteries (recommended)
for the transmitter, the receiver and the servos
- Charger (220V) for the rechargeable batteries or
quick charger to connect to a 12V car battery
- Glow plug (calorific value 1 or 3) and
- plug spanner
- Plug connector (long) for start battery and
- 2 Volt start battery or
- Plug connector with rechargeable battery as a unit
- Model fuel methanol/oil based, minimum share
5% - 10% nitromethane
- Tank bottle
CONTENT OF DELIVERY, NECESSARY ACCESSORIES3.1
Which type of fuel is the right one?
The selection of the fuel has an impact on the performance characteristic of the engine.
However, as a matter of principle:
- In the running-in phase, a special RC car fuel with approximately 15% nitromethane should be used.
- After the run-in of the engine (after a mere operating time of approximately 45 minutes), you can change to a fuel
with approximately 20% nitromethane.
- For maximum output, we recommend the max. percentage of 25% nitromethane
Use fuel for RC cars only!
The percentage of oil contained in fuel for RC plane engines is too small (too little lubrication), which causes the
engine to overheat, thus leading to serious damages.
The same is valid for vehicle gasoline.
Why is a tank bottle needed?
RC model car fuel is available in big bulks (canisters) only. Filling the tank by using a smaller, special
tank bottle with a small, curved pouring tube is significantly simpler. You also prevent spilling fuel
(expensive and poisonous).
Are more glow plugs necessary?
Glow plugs wear, especially in the running-in phase. Therefore, we recommend having some glow
plugs ready in case of need for a replacement. There are glow plugs with different calorific values;
the selection of the glow plug has a big impact on driving performance. For the running-in phase, you
should use a “hot” glow plug for high performance engines. After the running-in phase, you can use a
glow plug with a middle or a “cold” calorific value.
Use glow plugs for RC cars only! A wrong glow plug, such as e.g. for 4 stroke plane
engines, lets the engine run incorrectly and complicates the tuning.
Replacing the glow plug
To that effect, you need an extra long plug spanner (spider wrench SW 8, 9, 10 and 12), which can be used
also to unscrew the outer hexagonal screws.
Sparking the glow plug
A plug connector (long) with start battery or a plug connector with rechargeable battery as a unit
is inserted on the glow plug and heats the latter, so that the air-fuel mix sparks off and the engine
starts. When the engine runs smoothly, the plug connector can be removed.
ACCESSORY RECOMMENDATION
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
The engine transmits its capacity via the pinions on the clutch bell to the main pinion at the center differential.
Both rotary axes, i.e. the crank shaft, engine-sided, and the axis of the drive section to the front and rear axis, must be
aligned so that they are exactly in parallel. This prevents tensions in the drive section, premature wear of the pinions and
bearing journals as well as loss of power.
The parallel alignment of crankshaft and drive section must be checked every time before using the vehicle
and, if necessary, must be readjusted!
When the alignment is in parallel, the pinion on the clutch bell and the main pinion will run smoothly.
If there is too much play, this will destroy the toothed wheels in the long run; too little play destroys the bearing in clutch
and engine.
Checking the tooth backlash
- Place thin strips of paper between the pinion on the
clutch bell and the main pinion in the drive section.
- Move toothed wheel by hand;
the paper strips must not rip apart when the
wheel turns!
Readjusting
- Unscrew four screws of the engine mount fastener
on the lower side of the the mounting plate (chassis)
- Align engine laterally and fasten screws again tightly
- Unscrew four screws, at the top, on the engine support and adjust the engine lengthwise
TOOLS AND AUXILIARIES, CHECK LIST FOR PUTTING INTO OPERATION
3.2
3 PREPARATION
CHECK ALIGNMENT AND TOOTH BACKLASH OF DRIVE3.3
Monster Truck PREDATOR Pro is pre-assembled ready to drive (Ready To Run).
Before the first start, some basic adjustments must be carried out or checked and the necessary
accessories and auxiliaries must be prepared.
Go through the various points of the check list one after the other, and your model is then ready to run.
NOTE!
The instructions specific to position front / back / right / left
always refer to the longitudinal axis of the vehicle
in drive direction “forward”!
TOOLS
- Socket wrench (or flat wrench) 7 mm
- Flat wrench 5.5 mm
- Allen wrench 1.5 mm
- Phillips head (Ph Nr. 1)
AUXILIARIES
- Cable fastener
- Low viscosity machine oil for the air filter,
for lubrication and to protect the combustion
chamber against corrosive residues in the engine,
after operation („After Run”)
CHECK LIST FOR PUTTING INTO OPERATION
What must be done:
- Check alignment and tooth backlash of drive
- Function control of servos
- Check the range of the remote control transmitter
- Check basic carburettor setting
- Screw in glow plug
- Fill in model fuel
- Let engine runP
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- Remove lid of battery compartment on the lower side of the
transmitter.
- Insert 8 AA (rechargeable) batteries in the compartment,
observe the correct polarity!
- Close the lid again
- Open RC-box on the chassis
and
- remove the battery support
of the RC-box.
- Guide the antenna of the receiver
through the antenna guiding tube
- Stick the lower end of the antenna
guiding tube into the recess on the
cover of the RC box.
- Fasten the antenna wire on the
top at the guidance tube, by
wrapping adhesive tape around it
or by placing a rubber cap.
Do not shorten the antenna!
- Switch the transmitter on.
The blue LED in the leg of the
transmitter should light up.
If the LED does not light up, check
batteries /rechargeable batteries
and replace them, if necessary.
- Switch on the receiver with the
switch on the RC-box.
The servos must turn in neutral
position.
Always switch ON the transmitter
first then the receiver.
First switch OFF the receiver,
then the transmitter.
- Place 4 AA batteries (rechargeable
batteries) in the support.
- Observe correct polarity
and tightness.
- Place the battery support with the
cables and the plug in the RC-box
again.
- Carefully connect both red plugs.
- Guide the antenna wire through
the opening in the cover of the RC
box outwards.
- Rremove the receiver
- Unwind the wire of the antenna
3 PREPARATION
STARTING THE RC INSTALLATION
3.4
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
The steering servo is connected with channel 1 of the remote control transmitter to the steering wheel.
Structure of steering
The steering of “PREDATOR Pro” is designed as axle leg
steering.
At the same time the steering knuckle arms are connected with a
three-part steering link.
The pivoting movement of the servo control lever (1) with integrated servo saver has an effect on the steering linkage (2), on
one (3) of the two rigidly coupled, right-angled levers which are
attached rotatably to an axle between RC mounting plate and
chassis plate in the same plane as the steering rod. The second
lever arm (4) steers the centre part of the steering link (5) and
thus causes the steering angle of the wheels.
Turning right and left is limited by a mechanical stop of the steering knuckle arm against the axle leg support.
Function control:
- Support the model at the front in a way that allows the wheels to hang freely.
Because of the good adhesion of the tires and because of the weight of the vehicle, in the stand and
on the ground, the wheels will not follow your steering spontaneously and directly.
This however changes during operation.
- First, switch on the transmitter, then the receiver.
- Move the steering wheel (channel 1) towards the right and the left.
Now the wheels must drive in towards the right and the left!
If the wheels turn in opposite direction, change the Servo Reverse on the remote control
to position “REV” (Reverse).
- Release the steering wheel; now the wheels must turn in straight line again.
- If the wheels do not stand straight when the steering wheel of the remote control is in neutral position, correct
the position by adjusting the trim on channel 1.
The steering wheel limit stops must limit the right / left limit stops of the steering!
Right
Left
Neutral
(1)
(2)
(3)
(4)
(5)
FUNCTION CONTROL OF THE SERVOS
3.5
3 PREPARATION
STEERING SERVO
THROTTLE / BRAKE SERVO
The throttle/brake servo is connected to channel 2 or the remote control transmitter.
Mode of action and setting of throttle/brake linkage
With the throttle/brake linkage two functions are carried out at the same time via two servo steering levers.
By sliding the “carburettor slide” via the throttle linkage, the air supply to the engine is regulated.
At the same time, the idle nozzle needle (conical needle of a needle valve) is moved, thus, changing the amount of fuel that
flows through the carburettor.
If the throttle linkage is moved further than the idle position (mechanical limit stop of the carburettor slide),
the servo lever pushes against a spring buffer.
Now the sphere of action of the brake linkage comes to effect, it presses the brake shoes together via an eccentric tappet.
The positioning of the adjustment rings (the mechanical limit stops) of the stop springs on the throttle linkage and
on the brake linkage are adjusted ex works and tuned to the mechanical limit stops of the carburettor and the
disk brake.
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© REELY 01/0 7
Carburettor linkage
A visual check of the carburettor outlet is possible after removing or before attaching the
air filter.
- Idle speed position (max. 1 mm open carburettor outlet), if necessary, readjust the
adjusting screw at the idle speed (choke limit stop screw).
The idle speed adjusting screw is the little screw on the opposite side of
the carburettor slide.
The throttle / brake linkages have the following impact:
Full throttle: Carburettor slide fully pulled out, brake has no impact
Idle speed: Carburettor slide fully in, adjusting rings are loose on the brake levers.
Brakes: Throttle linkage presses against spring resistance, brake linkages press forward against the fully deflected
brake lever.
Function control of the throttle/brake servo
- Move the lever of the remote control (channel 2) towards the back (full throttle position).
The slide carburettor must now be completely pulled out, the carburettor outlet opened to its maximum.
The brakes have no impact.
If the slide carburettor does not start up when you actuate the remote control, set the Servo Reverse for
channel 2 to “REV” in order to reverse the direction of rotation of the servo.
If the slide carburettor does not start up fully, correct the servo travel at the rocker switch (channel 2) of the remote
control transmitter
- Release the lever of the remote control.
Now the slide carburettor must go back to the idle speed position (carburettor outlet opened to approx. 1 mm).
The brake still has no impact.
- Press the lever of the remote control forward as far as it will go (braking)
The slide carburettor must remain in the idle speed position (carburettor outlet opened to approx. 1 mm).
The servo lever at the carburettor linkage pulls against a spring resistance, the servo lever at the
brake linkage actuates the brake lever.
- Release the lever of the remote control again; now the brakes should be released again.
You can adjust the brake linkage by moving the adjustment rings at the brake steering levers accordingly.
Braking
Carburettor
outlet 1 mm
full
braking impact
Full throttle
Carburettor
outlet
completely
opened
Idle speed
Carburettor
outlet1 mm
Wheels turn
freely still,
no brake impact stil
3 PREPARATION
CHECKING
THE
RANGE
OF THE
REMOTE
CONTROL
TRANSMITTER
3.6
In order not to lose control over you model, you should, before each first start or after a crash, check the function
and the range of the RC system.
For the range test, it is sufficient to test the function of the steering servo.
Support the model at the front axle in a way that allows the wheels to hang freely.
-
Pull out the antenna of the transmitter completely and switch the transmitter on then the receiver.
-
Stride away from the model, approx. 50 m (engine does not run).
-
Place the steering wheel of the remote control and the corresponding
rocker switch
in neutral position
-
Move the steering wheel (channel 1) towards the right.
Now the wheels must drive in towards the right!
-
Move the steering wheel towards the left.
Now the wheels must drive in towards the left!
-
Release the lever of the remote control,
the wheels must turn back into the straight drive position.
Never drive the model with a remote control that is not functioning properly!
In the best case, “only” the model will suffer damages.
If the remote control does not function perfectly, check the charge state of the transmitter first, and
the rechargeable batteries of the receiver, then make sure that no other person is operating a vehicle on your frequency.
If the problem still persists, consult the trouble shooting table.
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
3 PREPARATION
CHECK CARBURETTOR BASIC SETTINGS
3.7
The engine of Monster Truck chassis „PREDATOR Pro“ is equipped with an ABC assembly.
ABC means “Aluminum”, “Brass” and “Chrome”.
Aluminum with its relatively small thermal expansion and small weight serves as material for
the piston. The light piston allows high revolutions and quick load-cycle changes through the
small mass inertia. The cylinder is made of brass with chrome-plated contact surface and
has a slightly conical shape which narrows upwards (in the range from 1 – 2 micrometer).
During operation, the upper part of the cylinder heats via the glow plug and the combustion
procedures; it expands, thus giving the cylinder sleeve its exact cylindrical shape for the
optimal tuning of the piston. In this way, piston rings are preserved, which reduces frictional
loss to a minimum and excludes leakages. These engines are manufactured according to
high technical outlays with precision machining. However, small manufacturing tolerances
cannot be avoided, just as little as slight unevenness and roughness of the material.
In addition, there aredeformations due to thermal and mechanical stress.
Thus, when driving the new engine, a certain break-in time must be observed.
During the break-in time, engine parts tune to one another, whereby maximal capacity is
reached and premature
wear is avoided.
Thus, the break-in procedure must be carried out with the highest accuracy!
The following must be observed during initial break-in:
- Low engine speed
- Rich fuel- air mix
- Short runtimes with cooling down phases
(each phase approx. 3 minutes)
- Runtimes (mere engine runtime) totaling approx.
45 minutes
Basic settings of the carburettor
The carburettor of Monster Truck “PREDATOR Pro” is
characterized by a material combination of a new type made of plastic and metal.
The low thermal absorption of the synthetic material, compared to a carburettor made of metal only, reduces the evaporation of the fuel
mixture already in the carburettor.
Thus, the fuel supply can be more precise, even with a hot engine and can be regulated in a simpler way.
Throttle stop screw (idle speed-adjusting screw)
The throttle stop screw is the small screw next to the idle speed-mix
adjusting screw. It is already pre-adjusted;
a readjustment should not be necessary. The idle speed adjusting
screw regulates the position of the slide carburettor (the choke
limit stop) and therewith the carburettor outlet in idle speed.
We recommend a carburettor outlet of approximately 1 mm.
Turning the adjusting screw clockwise widens the outlet, turning it
anticlockwise causes the
slide to retract further, which reduces the opening.
Main nozzle needle (mix adjusting screw)
The main nozzle needle is located above the fuel supply to the carburettor. It is adjusted for the first start of the engine
and should not be modified yet.
The main nozzle needle regulates the air / fuel mix by full throttle. Turn the screw clockwise in order to make the mix
“leaner” (to reduce the proportion of fuel) and turn it anticlockwise in order to make the mix “richer”.
In the basic setting for the first start, the main nozzle needle must be completely screwed in then unscrewed by two to
three rotations.
Schiebevergaser (Abb. modellähnlich)
Throttle stop screw
Idle speed mixadjusting screw
Main nozzle
needle
Air suction opening
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© REELY 01/0 7
Idle speed- mix adjusting screw
The idle speed mix adjusting screw is the little screw on the side of carburettor linkage.
It is adjusted for the first start and should not be modified yet.
The idle speed mix adjusting screw regulates the air /fuel mix in idle speed and in
the transition interval to full throttle.
Turn the screw clockwise in order to make the mix “leaner” (to reduce the proportion of
fuel) and anticlockwise, if the mix should be “richer”.
Depending on fuel, glow plug used and environmental conditions, small modifications in
the settings might be necessary at a later time.
In order to reset the factory setting proceed as follows:
- Open the slide carburettor completely
- Keep the slide open and turn the idle speed mix adjusting screw clockwise as far as it will go.
- Now unscrew it turning it by 7.5 rotations anticlockwise.
3 PREPARATION
Fuel
The selection of the appropriate fuel has a significant impact on the performance characteristics of the engine.
The addition of nitromethane in the model fuel increases the ignitability of the fuel and thereby the performance of the
engine.
The oil part in the fuel ensures the lubrication of the engine; the engine is “self lubricating”.
In the break-in phase, a special RC car fuel with max. 15% nitromethane should be used.
After the regulatory run-in of the engine (after a mere operating time of approximately 45 minutes), you can use a fuel with
a percentage of max. 25% nitromethane.
Never use fuel for RC plane engines! The percentage of oil in such fuels is too low (too little lubrication), which
causes the engine to overheat, thus leading to serious damages.
Glow plug
The selection of the glow plug has also an impact on the performance of the engine. For the break-in phase, you should
use a “hot” glow plug (also for high performance engines). After the break-in phase, you can change to a glow plug with
middle or “cold” calorific value.
Never use glow plugs for 4-stroke plane engines! A wrong glow plug causes the engine to run incorrectly
and complicates the tuning of the engine.
Surge and overheating can destroy the glow plug. Take note of the power data and preheat with the correct tension; disconnect the tension immediately after the engine has started.
Air filter
Never drive without air filter!
The air filter prevents dirt from penetrating into the engine via the intake air. Already small
dust particles that get between cylinder liner and piston via the intake air, cause the piston to get stuck or
to get seized, which can destroy the engine and lead to consequential damages in the drive section.
Moisten the air filter additionally with a thin fluid machine oil in order to filter out the smallest dust particles.
RECOMMENDATION FOR OPERATION
3.8
The pre-mounted engine was manufactured with precision machines in accordance with the latest technology.
Manufacturing tolerances are very low.
The break-in procedure must be carried out with the highest accuracy.
- The carburettor is already roughly pre-adjusted.
Fine tuning of idle speed and full throttle can only be carried out with a well run in engine
.- Before using the engine blow it out with compressed air.
Thus you can be sure that the combustion chamber is free from impurities, which could penetrate into the engine.
- Insert a glow plug with a calorific value of 1 or 3.
- Oil the air filter slightly in order to filter out dust particles
PREPARATIONS
STARTING THE ENGINE
3.9
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
3 PREPARATION
Insert the glow plug!
Prop up the model for starting so that the wheels hang freely in the air and that the main pinion
on the lower side does not get blocked!
- Open the lid of the tank and fill in the fuel.
- Use a special tank bottle, in order to avoid spilling.
Only use model fuel for R/C cars!
Never use gasoline or model plane fuel!
- Pull the starter cord (a) several times slowly, in order to ingest fuel
in the carburettor or
- operate the tank pump to pump fuel into the carburettor.
- Keep doing this until no more air bubbles are seen in the fuel hose
(c) and the fuel just barely gets in the carburettor.
NOTE!
Do not pull the starter cord all the way but rather to approxima
-
tely 3/4 of its length!
Determine the length of the starter cord by pulling slowly without
ignition!
Never pull out the starter cord with force!
- Place a plug connector with fully charged start battery on the glow
plug.
- Pull the starter cord with energy, until the engine starts up, while
you hold the model firmly with one hand.
- When the engines starts to run, let go of the starter cord and
remove the plug connector again.
Leave the plug connector connected to the engine only briefly.
Otherwise, the glow plug could burn out prematurely.
Switch off engine
- Cut off the air supply to the carburettor.
- Block the exhaust pipe with a piece of cloth, or
- Stop the fly wheel of the engine on the lower side of the car body with a piece
of cloth / with gloves.
The fuel supply should not be disconnected as otherwise the engine could over
-
heat.
NOTE! If, after
several unsuccessful start activities, the starter cord can
only be actuated with excessive
use of power, too much fuel got into the combustion chamber and the
crankcase. The engine is “flooded”. Refrain from further start trials and
remove excess fuel
in order to avoid damaging the starter cord and the
engine!
For this purpose, proceed as follows:
- Carefully turn in the main nozzle needle clockwise, as far as it will go.
- Unscrew the glow plug and check its glow function
- Place a piece of cloth on the engine and pull the starter cord 5-6 times (3/4 of the length!):
Fuel is pumped out and evaporates.
- Insert the glow plug again and turn the main nozzle needle by three rotations anticlockwise.
- Repeat the start activity
If the engine does not start up, at the latest after 10 or 12 times, proceed as described above or try to
eliminate the problem with the help of the trouble shooting table!
STARTING THE ENGINE
(a)
(b)
(c)
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© REELY 01/0 7
Fuel:
The addition of nitromethane in the model fuel increases the ignitability of the fuel and thereby the performance of the
engine.
Use in the break-in phase a model fuel with a small percentage of nitromethane in order to avoid overheating
the engine. Furthermore, the fuel should have a higher percentage of oil (“rich” carburettor setting), so that the lubrication of the engine is improved, until piston and cylinder liner are run in.
After having filled in the fuel and started the engine as described above, you can start the run-in of the engine.
1. Initial break-in phase:
In order to be able to use the full power spectrum later on, the engine should have two to four tank fillings at
a “richer” carburettor setting, and run with changing throttle.
This is indicated by the strong white smoke emission from the exhaust pipe.
After each engine running (tank filling), allow for a sufficient cooling phase.
Afterwards, the mix can be made leaner by screwing in the main nozzle needle step by step.
- Leave the plug connector inserted and let the engine warm up for approximately 1 minute without accelerating.
- If necessary, unscrew the main nozzle needle a little (the flow rate will be bigger)
- Remove the plug connector after one minute warming up phase.
- Let the engine run for about 2 – 3 minutes with cooling down phases in between.
Increase the speed slightly with short throttle bursts.
The engine runs very roughly and the model moves very reluctantly.
- Switch the engine off after 2 –3 minutes
- Let the engine cool down for approximately 10 minutes.
2. Initial break-in phase
- Set the engine slightly leaner by turning in the main nozzle needle by an eighth of a turn and start the engine again.
- Let the engine run again for about 2 – 3 minutes with cooling down phases in between.
Now the engine should accept the throttle a little better, but there is still smoke.
If the engine revs up briefly then stalls, unscrew the main nozzle needle slightly once more.
- Stop the engine again and
- let it to cool down for 10 minutes.
- Repeat this procedure and make the mix slightly leaner each time.
3. Initial break-in phase
Three more tank fillings, the vehicle can now be run at a slow speed (max. 1/2 throttle).
A mix that is too lean causes overheating and engine seizure.
For a long engine life you should prefer a slightly rich carburettor setting and a fuel with a sufficient percentage of oil (min.
20%) is favored.
Overall, the real driving time (engine run time) should be approximately 45 minutes.
After this time, the engine should be run-in. You know that the engine is run in when it can be cranked up in a cold state
and without glow plug and without noticeable resistance.
Now you can operate the engine with full power.
- Enrich the mix by adjusting the main nozzle needle again, but keep the setting lean so that the model runs perfectly.
NOTE! It is always extremely important not to make the mix too lean!
Keep in mind that the engine lubrication is effected via the oil contained in the fuel.
Too little oil in the air/fuel mix causes engine overheating and piston seizure due to inadequate lubrication.
During operation, a light white trail of smoke coming out of the exhaust pipe should always be visible.
If this is not the case, stop the engine immediately and enrich the mix.
Also make sure that sufficient air circulates around the cylinder head, in order to avoid overheating.
If necessary, effect a corresponding opening in the car body.
The optimal engine operating temperature is approx. 100 – 120°. Check the temperature with a drop of water
on the cooling head. If the water evaporates abruptly, the engine is too hot.
In operating temperature, the water evaporates in 3 – 4 seconds.
3 PREPARATION
RUNNING-IN REGULATIONS FOR THE ENGINE
3.10
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
The fastening elements for the car body are already pre-assembled in the contents of the delivery of the PREDATOR Pro
Chassis.
Before installing the car body, the boreholes for the car body supports and antenna passage
as well as for the fitting parts must be mounted. Use a special car body drill.
First of all, mount the fitting parts such as bumper, rear-view mirror, roll-over bar and auxiliary
headlights.
Installing the car body
- Apply colored chalk or slow drying paint on the edges of the car body support and
- Place the car body as exactly as possible on the chassis.
- Remove the car body again and
- Drill holes into the car body at the places marked with paint (chalk) for the
mounting parts of the car body.
- Place the car body and fasten the latter with the car body splints
For a simpler handling, bent up the splints slightly.
- Determine the position of the antenna tube on the car body and
- Drill here also a hole for the antenna passage.
- Make openings for the starter cord, the tank shutter and the cooling head.
4 DRIVE OPERATION
- Make sure that the rechargeable batteries of transmitter and receiver are fully charged.
- Check the range of the remote control transmitter and the function of the RC- System.
- Always try to drive the model at high revolutions!
- Avoid brief, strong throttle bursts when you want to drive slowly!
- Avoid frequent slow driving with slipping clutch!
- Always drive with attached car body.
Thus, you protect yourself against burns if you touch the engine and the manifold by accident and you protect the
components from falling stones.
Bear in mind that the operation of remote controlled vehicles has to be learned step by step.
Start with simple driving exercises, e.g. circular driving
- Use simple plastic cups as pylons to delimit a course.
- Get used the driving behavior in curves.
- Practice steering when the model runs towards you!
MOUNTING THE CAR BODY
Motor
The 2,76 ccm engine of the Monster Truck Chassis “PREDATOR Pro” is air-cooled. This means that the air stream takes
on the cooling of the engine (air cooling).
This is why you should try to avoid accelerating the vehicle with frequent, strong load changes (short throttle bursts from
low rev range and jerkily lowering the revs).
The brief high revs strongly heat up the engine, without there being appropriate cooling through wind, as this would be the
case at a drive with constantly high revolutions (high speed). As a result of overheating the engine, the piston may get
stuck in the cylinder liner (piston gets stuck) and suddenly block the drive. This could cause consequential damage of the
entire drive section.
Drive in part-load operational range with revs that correspond to the desired speed.
However: When driving slowly continuously, the cooling of the engine through air stream is guaranteed, but instead,
there may be damages on the clutch (wear, overheating through slipping clutch).
Clutch
The power of the engine is transmitted via the center differential to the drive section.
- At idle speed the clutch doesn’t yet grip, the model remains stationary with engine running.
- When the revolutions are slowly increased the clutch “slips”, the vehicle moves forward or starts to move slowly.
As with a “real” vehicle, constant slipping of the clutch can cause the clutch to “smoke away” or “burn off”.
- Only at high engine revs does the clutch start to “engage”, the engine speed is transmitted without any slip to the
drive section. The wear on the clutch linings is now at its lowest.
- Frequent, strong load changes by brief short throttle bursts and jerky lowering of the revs also reduce the life of the
clutch linings. With short throttle bursts as well as by letting the clutch slip, you achieve a slow speed, but at the
expense of the clutch.
EFFECTS OF MANNER OF DRIVING ON INDIVIDUAL COMPONENTS
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© REELY 01/0 7
5 TUNING
After the run-in phase of the engine, you can start the fine tuning to increase the performance.
To that effect, optimize the mix preparation for idle speed and change-over at the idle speed mix adjusting screw and
with full throttle at the main nozzle needle.
This fine tuning is significantly simplified thanks to the carburettor of a new type with the material combination aluminum/
plastic. Carburettors made of metal only heat up a lot during operation which causes fuel parts to evaporate already in
the carburettor.
Thus, the carburettor setting selected with a cold engine does not remain constant during operation.
The small heat absorption of the synthetic material prevents this effect.
Adjust the main nozzle needle (full throttle mix)
- Start the engine and remove the plug connector. Let the engine warm up for approximately 1 min.
- Drive the model as usual. If it seems that the engine runs too rich, make the mix leaner by screwing in the main
nozzle needle by 1/16 rotations respectively, until the desired setting is reached.
- Make sure that the mix is not too lean.
A light white trail of smoke should always be visible coming out of the exhaust pipe.
For an even increased performance, you can change to a fuel with up to 30% nitromethane
.However, there is the danger that the engine would show no satisfactory road performance any more, if you
go back to a fuel with a lower percentage of nitromethane.
If you want to use a fuel with a high percentage of nitromethan continuously, we recommend however,
that you replace the present cylinder head washer with a 0.1 mm (thicker) washer, in order to reduce compression.
If you do not reduce the compression, an overheating of the engine and a defective run can be the consequences!
Adjusting the idle speed mix adjusting screw
- Start the engine and adjust the main nozzle needle, as described above.
- Reduce the speed until the centrifugal clutch does not engage any more and that the wheels do not turn any more
when you lift the model off the ground.
- Let the engine cool down in idle speed for approximately 10 – 15 seconds.
- While you are holding the model with your hand, drive at full throttle once briefly and strongly.
Make sure not to touch moving parts!
- If the engine stalls as soon as you run at full throttle, then the idle speed mix is too lean.
- Enrich the mix by unscrewing the screw by 1/16 rotations while the engine is switched off.
- Restart the engine and repeat the procedure until the speed transition from idle speed to full throttle is effected
softly and spontaneously. A small delay in response is normal.
- If the engine smokes strongly during transition from idle speed to full throttle and sounds very rough,
then the mix is too rich.
- Make the mix leaner by screwing in the screw by 1/16 rotations while the engine is switched off.
- Restart the engine and repeat the procedure until the speed transition from idle speed to full throttle is effected
softly and spontaneously. A small delay in response is normal.
- Drive the engine as usual in order to get a feeling of how the engine reacts to load changes.
- Modify the setting until the performance characteristics correspond to your expectations.
ENGINE FINE TUNING
5.1
Bearing
Overheating the engine and/or the clutch also has an effect on the bearings of the clutch bell.
Leaking and toughening of the bearing grease (running dry of bearing) as well as different expansion of the balls and
the ball bearing case in the case of excessive heat, can lead to a jamming of the balls. If the balls can no longer move
freely, there are frictional losses and therewith an additional heating up of the engine shaft.
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
The four spring elements of the all-wheel suspension of the chassis consist each of a
coil spring in whose center and oil dampened suspension is located.
The four oil dampened suspensions are fastened to the lower transverse links and to the
“damper plates” on the differential housing.
On the top, the coil springs rest against a screw ring (3) on the outer tube of the shock
absorber and a plate on the bottom end of the piston rod. Turning the screw ring towards
the top relieves the spring, the suspension gets “softer”. Turning it downward increases
the spring preload, the suspension gets “harder”. The spring preload can thus be finely
adjusted according to surface and manner of driving.
For a rough adjustment of the damping, the shock absorbers can be fixed to different steering points on the damper plates and transverse control arms.
The setting of the suspension influences not only the ability of the model to “even out” road unevenness,
but also the behavior in bends.
This driving behavior is called to “oversteer” or to “understeer”.
Over-steering or under-steering driving behaviour can be the result of uneven cornering powers of front and rear axle due to
incorrect setting of the camber.
Understeering driving behavior:
The model is difficult to steer around the bend, “pushes” the front wheels outwards (too much traction of the
rear axle or too little traction of the steered front axle.
As a counter measure the suspension should be set harder at the rear (or softer at the front).
Over-steering driving behavior
The model “pulls” in the bend, the rear tends to swerve (too little traction on the rear axle or too much traction
at the steered front axle).
As a counter measure the suspension should be set softer at the rear (or harder at the front).
As a basic setting, the front axle should be set approximately 5 mm lower than the rear axle!
Check the impact of the shock absorbers:
- Lift the model at the rear axle and drop it.
- The model should not deflect until lock and only top out once without any reverberation!
- Test the shock absorbers of the front axle in the same way.
Setting the spring preload
- Increasing the spring preload
Turn the screw ring on the outer tube of the shock absorber
clockwise.
The suspension becomes harder.
- Decreasing the spring preload
Turn the screw ring on the outer tube of the shock absorber
anticlockwise.
The suspension becomes softer.
Tuning
To further optimize the damper characteristics, we offer, in our accessories, silicon oil for the shock absorbers in different viscosities!
SPRING PRELOAD
(1) (2) (3)
SETTING THE DAMPING
5.2
5 T
UNING
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© REELY 01/0 7
The front shock absorbers have each two attachment point at the transverse control arm and four further attachment points
at the shock absorber bracket on the top used in serial production.
The rear shock absorbers have each two attachment points at the transverse control arm and each four further attachment
points at the shock absorber bracket at the top.
By adjusting the shock absorbers you can achieve a change in the response behavior of the suspension by modifying
the angle of attack, besides achieving a higher/lower setting of the chassis.
ADJUSTING THE SHOCK ABSORBER
Adjusting the shock absorbers
- Adjusting the upper or the lower transverse control arms
to a steepest angle of attack reduces the progressivity.
The vertical relative movement of the chassis is directly
guided into the suspension, the damper effect is instant,
the suspension is already harder following a small deflection. At the same time, the vehicle is raised.
- Adjusting the shock absorber to a flatter angel of attack
increases the progressivity. In the case of a flatter angle
of attack, the chassis must have a deeper spring deflection in order for the suspension to react; i.e. the suspension reacts softly at first and then becomes increasingly
harder.
The position of the vehicle is lowered.
Preload and attachment points of the shock absorbers of an axle must be adjusted identically right and left!
Direction of deflection
Direction of deflection
Vertically to the direction
of deflection of the wheel
(=flattest angle of attack
0°), no power is induced
and the shock absorber has
no effect.
The power is directly
induced in parallel to the
direction of deflection
(=steepest angle of attack,
90°) of the wheel, and the
shock absorber serves its
maximum use.
Front
Rear
MECHANICAL LOWERING
For lowering the chassis, it is possible to
mechanically limit the top-out path.
To do so, one screw each can be screwed in from the top into the bottom transverse links, supporting against the chassis.
5 TUNING
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
The camber is the inclination of the wheel level as viewed from the front (vertical).
Negative camber (wheel top edges point inward) on the front wheels increases the cornering power of the wheels when
driving in bends; the steering reacts more directly, the steering forces are reduced. At the same time, the wheel is pushed
onto the axle leg in the direction of the axis.
This stops an axial bearing clearance, the driving behavior is calmer.
A negative inclination on the rear wheels reduces the tendency of the rear of
the vehicle to swerve in bends.
By setting a negative inclination, the wear on the inside of the tires increases.
However, this effect can be compensated by setting a toe-in.
Fine tuning of inclination on front and rear wheels
- Twist clamping screw in the upper transverse link
clockwise:
The upper edge of the wheel is pulled inward in
direction
“negative inclination”.
- Twist clamping screw in the upper transverse link
anticlockwise:
The upper edge of the wheel is pulled outward in
direction
“positive inclination”.
The alignment designates the position of the wheel level to the driving direction.
During the drive the tires are pushed apart in the front because of the rolling friction and this is why they are no longer
exactly parallel to the drive direction. To balance, the wheels of the stationary vehicle can be set, so that they point slightly
inward.
This toe-in effects an improved lateral cornering of the tire and therefore a more direct response of the steering If a milder
response of steering is desired, this can be achieved accordingly by adjusting a toe-out , i.e. the wheels of the stationary
vehicle point outward.
The right/left threaded rods with the spanner flat (1) for the separate wheel alignment of the front wheels are located in the
right and left threaded rod, between the steering knuckle arm and the steering knuckle centre part.
For a rough adjustment of the track, the outer steering links can be screwed to the axle leg at one more fixing point each
(2).
The toe-in of the front wheel must not exceed 4°.
SETTING THE CAMBER INCLINATION
5.3
5 TUNING
SETTING THE ALIGNMENT
5.4
Toe-out
Setting a toe-out makes the
outer part of the tires wear faster.
Toe-in
Setting a toe-in makes the
inner part of the tires wear faster.
Direction of driving
(1)
(2)
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© REELY 01/0 7
At certain intervals, maintenance work and function controls that ensure trouble-free operation and
roadworthiness for a long time, must be carried out.
Engine vibrations and shocks during drive operation can loosen parts and screw connections.
Therefore, check before each use:
- The tight position of wheel nuts and of all screw fittings;
when replacing screws, secure the latter with screw-lock-laquer
- the secure position of the servo control lever on the servo shaft
- the position and the state of fuel hoses and air filter
- the laying of cables
- the charging state of the rechargeable batteries of transmitter and receiver
Cleaning
- After driving, clean the entire vehicle of dust and dirt, use compressed air and / or a special spray detergent.
Pay particular attention to the bearings. Occasionally, remove the wheels and clean the ball bearing from dust
and deposits.
After cleaning, the movable parts must be re-lubricated.
After having lubricated the bearings remove any leaking oil and grease, since this is where dust can settle
particularly well.
- Clean the cooling fins of the cooling head regularly with a toothbrush, in order to ensure an optimal heat
dissipation.
Fuel system, engine
- Impurities must not get into the tank or in the carburettor and / or certainly not in the engine
. Such impurities can cause misfiring under load or a bad idle speed setting
. In the worst case a foreign body between cylinder lining and piston can result in a stuck piston or a piston seizure.
For safety purposes, mount a fuel filter between tank and carburettor, in order to filter existing suspended
particles out of the fuel.
- Use fuel for RC cars only!
- Always use fresh fuel and keep the tank lid firmly shut.
With time, model fuel absorbs humidity from the air. This humidity lowers the performance of the fuel and causes the
engine to run incorrectly as well as corrosion in the engine.
- Empty the tank if you do not use the model for several days.
The volatile components of the fuel nitromethane and methanol evaporate leaving oil behind; the latter sets down,
enriches the mix and can clog lines.
- When ending drive operation for the day, unscrew the glow plug and put some drops of engine oil
“After Run” (low viscosity machine oil) in the cylinder.
Insert the glow plug again and turn the model a few times over and swing it, so that the oil can be evenly distributed
in the combustion room. This prevents corrosion.
In case of longer drive pauses, e.g. “to overwinter”, put 2 – 3 drops of anticorrosion oil (accessories) in the
cylinder
- Fix fuel hoses on the connector nipples with thin cable binders or special hose binders (accessories).
Otherwise the oil in the fuel can cause slipping.
Air filter
The air filter prevents dirt from penetrating into the engine via the intake air. Foreign bodies which penetrate via the
intake air between cylinder lining and piston can cause the piston to get stuck or piston seizure, which would then damage
the engine and cause consequential damage in the drive section.
- Clean the air filter with paraffin or low viscosity machine oil (air filter oil, accessories).
If you want to clean the air filter with a detergent and water, then rinse it thoroughly afterwards.
Soap residues could get into the engine and damage the lubricating film.
Oil the air filter afterwards with air filter oil.
- Never drive without air filter!
- Fasten the air filter with a thin cable binder.
Lubrication
All moveable and bedded parts must be lubricated with a low viscosity machine oil or spray grease after cleaning and
after each use.
Driving by adverse atmospheric conditions and ambient conditions
The components of the RC system are not waterproof!
Package the servos in plastic film in order to protect the parts against splash water, wet grass and humidity (fog, drizzle),
as well as against dust and other impurities.
6 MAINTENANCE
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
7 TECHNICAL DATA
Engine:
28er Combustion engine
with ABC assembly, two chamber resonance exhaust silencer and
slide carburettor in metal/plastic combination
Displacement: 2.76 ccm
Power: 1.10 kW / 1,5 PS
Engine speed: 30.000 rpm
Bore: 16.6 mm
Stroke: 13.7 mm
Weight: approx. 292 g
Power transmission:
All-wheel drive: via cardan shafts to front and rear axles
enclosed differential in the front and rear axle,
main pinion made of steel
All drive axes are supported by ball bearings.
Transmission ratio: Main pinion (48Z / clutch bell (13Z) = 3.69
Chassis: Support plate and RC mounting plate made of Duralumin,
extremely light, firm and warp resistant
damper plates made of aluminum, CNC machining
Chassis frame:
Front wheel suspension: Twin control arm suspension
Clamping screw in the upper transverse control arm
Rear wheel suspension: Twin control arm suspension
Clamping screw in the upper transverse control arm
(inclination front / rear adjustable)
Steering links: middle part made of Duralumin
Alignment roughly adjustable
Axle leg: Aluminium
Brake: Disk brake with aluminum brake disk
Suspension: Spring struts with aluminum oil dampened shock absorbers,
spring preload via screw rings, adjustable,
steering point adjustable
Tire equipment:
Front / rear: Monster Truck-tires,
Width: 65 mm, Ø 120 mm
MEASURE AND WEIGHT
Monster Truck Chassis PREDATOR Pro
Total length Wheel base Width Wheel track Height Weight with engine
(as in delivery)
410 mm 270 mm 320 mm 264 mm 230 mm approx. 2200 g
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© REELY 01/0 7
8 TROUBLE SHOOTING
RC-SYSTEM
RC-System does not function Batteries/rechargeable batteries of transmit-
ter and/or receiver
are empty
Replace the batteries/rechargeable batteries of
transmitter and/or
receiver
Batteries/rechargeable batteries are inserted
incorrectly
Check the polarity of the batteries/rechargeable
batteries
Plug of batteries/rechargeable batteries of
receiver is loose
Firmly insert the plug again
Range of transmitter too small Batteries/rechargeable batteries of transmit-
ter and/or receiver are weak
Replace the batteries/rechargeable batteries of
transmitter and/or receiver
Receiving power of the antenna is too low Pull out the antenna of the transmitter completely
Completely unwind the antenna of the receiver
and guide it upwards
The antenna of the transmitter is not pulled
out
Pull out the antenna completely
The antenna of the receiver is not pulled out
on its full length
Pull out the wire of the antenna completely.
The antenna of the receiver is cut Repair the receiver
Servos do not respond correctly Batteries/rechargeable batteries of transmit-
ter and/or receiver are weak
Replace the batteries/rechargeable batteries of
transmitter and/or receiver
Toothed wheels in servo links do not engage
or are defective
Repair the servo
Adjusting rings on the servo motor are loose Readjust the adjusting rings; use
factory settings
Servo Reverse Switch was
set on „REV“ accidentally
Switch the Servo Reverse onto „NORM“
RC-System functions incorrectly,
while the engine is running
Crystal of receiver is loose Reinsert receiver crystal
Plug of batteries/rechargeable batteries of
receiver is loose
Firmly insert the plug again
Receiver damaged, e.g. after a crash Repair the receiver
ENGINE OR FUEL SYSTEM
The engine does not start Defective glow plug or empty start battery Replace glow plug, Charge start battery
Start battery defective Replace start battery
Fuel tank is empty or carburettor is not
filled
Fill fuel tank and pump fuel in carburettor by pulling the recoil starter cord several times
Carburettor not correctly set Reset idle speed and main nozzle needle
Fuel is old or dirty Replace fuel and check fuel filter
Combustion room full with fuel (flooded) Unscrew glow plug and proceed
as described in the corresponding chapter
additional air is sucked via fuel line or
engine
Check/replace fuel hoses and/or tighten all engine
screws
Servo links not properly adjusted Place servo in neutral position and readjust
Fuel line, air filter or exhaust
blocked
Clean blocked parts, if necessary, replace
Engine does not get fuel Main nozzle needle fully turned in Readjust the main nozzle needle according to
factory setting
Idle speed mix too lean Readjust the idle speed mix adjusting screw
to factory setting
Fuel hoses bent Check and straighten fuel hoses
Fuel tank defective Replace fuel tank
Engine starts, but stops again Fuel tank is empty Fill fuel tank
Fuel line, air filter or exhaust blocked Clean blocked parts, if necessary, replace
Carburettor not correctly set Reset idle speed and main nozzle needle
Engine overheats Check the temperature. Above 150°, the fuel mix
must be enriched. Check if the wheels can move
freely.
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Operating Instructions 4WD Monster Truck Chassis Item No. 23 31 87
8 TROUBLE SHOOTING
Engine does not run smoothly,
responds badly
Incorrect or defective glow plug Insert the necessary glow plug
Wrong or old fuel Fill the correct fuel
Dirty air filter Wash the latter then use air filter oil
Mix too rich Adjust the main nozzle needle to a leaner mix
Idle speed mix too lean Readjust the idle speed mix adjusting screw
to factory setting
Idle speed mix too rich Setzen Sie die Leerlauf-Gemischregulierschraube
auf die werkseitige Einstellung zurück
Additional air is sucked via fuel line or
engine
Check/replace fuel hoses and/
or tighten all engine screws
Too little pressure from exhaust line Check exhaust line and, if necessary, replace
Engine overheats Mix too lean Adjust the main nozzle needle to a richer mix
Car body too compact Ensure sufficient air supply and dissipation
to the engine by cutting the car body correspondingly.
Wrong fuel Use RC car fuel only
Engine speed does not decrease Throttle stop screw is misaligned.
Reset the throttle stop screw to factory setting
Engine sucks additional air Check and tighten all engine screws
One or several joint rings on the carburettor
are defective
Replace the defective joint rings
CHASSIS
Model pulls to one side Steering trim is misaligned Correct the neutral position on the remote con-
trol
Alignment right and left is different Reset the alignment on both sides onto 0°
Wheel damaged on one side or bearings
defective
Remove the wheel, clean the bearings and, if
necessary, replace
Model can be controlled but only
with difficulty
Servo links not properly adjusted Place servos in neutral position and readjust
Receiving power of the antenna is too small Pull out the antenna of the transmitter complete-
ly. Completely unwind the antenna of the receiver and guide it upwards
Batteries of transmitter and/or receiver empty Replace batteries or recharge rechargeable
batteries
Brake has no impact Brake linkage misaligned Correct the adjustment of the brake steering
lever Brake disk worn out Replace brake disk
Clutch does not engage Clutch shoes worn out or defective Replace clutch shoes
Clutch bell worn out or defective Replace clutch bell
Fly wheel is loose Retighten fly wheel.
Clutch does not unlink Spring for clutch shoes worn out or defective Replace springs
Model does not function Main pinion defective Replace main pinion
Damaged pinions in the differential Replace pinions
Centrifugal clutch set too loose Reset centrifugal clutch
Damping not soft and accessible One or several dampers are jammed Clean and/or disassemble dampers
Piston rod bent Repair the piston rod
Shock absorbers lose oil A damping component is defective Check and replace the corresponding part
Sealings worn out Replace sealings
Model rolls over towards the back
during acceleration
Centrifugal clutch set too taut Loosen the adjusting screw until the model runs
smoothly
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