Walkera G120EFI User manual

www.walkera.com
Control Power System
User Manual
April 24, 2020
V1.1

2
1.0 Product Summary
2.0 Security Summary
4.0 Specifications
5.0 Preparations
2.1 Environment
2.2 Prechecking
2.3 Operation
5.1 Installation instructions
5.2 Connecting lines
5.3 Oil circuit connection diagram
5.4 Fill in fuel and coolant
5.5 Running in
7.1 Engine startup
7.2 Engine Operation
7.3 Close Engine
8.0 Engine Maintenance and Warranty
8.1 Engine Maintenance
8.2 Engine Warranty
9.0 Common faults
9.1 Startup Difficulty
9.2 Performance degradation
10.0 List of items
Contents
3
4
4
4
7
8-9
10-12
16
16
16
13
14
17-18
17
19
19
20-21
14
15
5
6
3.0 Parts Introduction
3.1 Engine Introduction
3.2 G120EFI Control Box Introduction
6.0 Description of PWM control signal of the remote controller
7.0 Operation

3
1.0 Product Summary
The power system has certain safety risks and is not suitable for people
under 18 years of age. Please read the instructions carefully before operation and
use them correctly according to the instructions.
Thank you for purchasing the Walkera G120EFI control power system.
The EFI control power system has the following advantages:
Electronic injector has accurate fuel supply control, quick response, good fuel atomization effect,
reduced fuel consumption and exhaust pollution of engine.
Electronic Control Unit (ECU) responds quickly to the change of throttle, improves the engine's
handling and acceleration performance, and maintains good dynamic performance indicators;
allows the engine to adopt a higher compression ratio, and improves the engine's thermal efficiency.
Electronic Control Unit (ECU) has built-in ignition control, which directly drives the EFI igniter to
achieve stronger power performance and idle speed stability.
Stronger environmental adaptability, adaptability at different altitudes, temperatures and humidities.

4
2.0 Security Summary
2.1 Environment
Use in open spaces away from crowds.
Recommended height below 4km above sea level.
It is used in the environment of - 20℃~40℃.
Use in legal areas
2.2 Prechecking
The fuel tank position needs to be higher than the oil pump position to ensure smooth oil supply.
Check the fixing parts of the power system to ensure that the screws and nuts are not loose.
Check oil kettle and fuel pipeline to ensure that the fuel is leak free.
Check the water cooling kit of the power system to make sure it is connected properly and securely.
Make sure the parts are intact. If any parts are dirty, deteriorated or damaged, please clean or
replace them before use.
Make sure the tank is filled with fuel and the cooling tank is filled with coolant.
Make sure there are no air bubbles in the coolant circuit and the coolant will circulate normally
after power on.
Make sure that the oil pump has entered the oil after the power is turned on,
the gasoline in the return pipe is flowing back to the fuel tank continuously.
2.3 Operation
I t is strictly forbidden to disconnect the power battery (aircraft battery)
after the engine is started.
Do not approach engine and propellers of aircraft that are in operating.
The gasoline used in the engine is flammable and explosive liquid.
Please keep away from open flames and prohibit smoking.
Altitude and power comparison table
Altitude 0m Power 100%
Altitude 1000m
Altitude 2000m
Altitude 3000m
Altitude 4000m
Power 93%
Power 85%
Power 76%
Power 64%

5
3.0 Parts Introduction
11
2
233
4
6
7
8
5
3.1 Engine Introduction
1. Spark plug
2. Cooling cylinder cover
3. Cylinder liner
4. Casing
5. Generator
6. Silencer
7. Nozzle
8. Air filter

1 2 3 4 5 6 7 Nozzle
Starter Oil pump
DC_12V_IN 12V 12V 4 3 2 1
UART1SWD UART2 Battery
voltage
6
3.2 G120EFI Control Box Introduction
1. SBUS
2. Ignition signal
3. Speed signal
4. PWM-OUT
5. Servo 1
6. Servo 2
19. LED light
20. LED light
21. Battery voltage
22. UART1
23. UART2
24. SWD
13. 12V
14. Sensor 1
15. Sensor 2
16. PWM-IN1
17. PWM-IN2
18. LED light
7. CDI power supply
8. starter
9. Oil pump
10. Nozzle
11. DC-12V-IN
12. 12V
1
2
3
4
10
5
6
7
8 9 11 12 13 14
15
16
17
18 19 20
21
222324

7
Weight
Size (L × W×H)
Weight
Size (L × W×H)
Weight
Size (L × W×H)
1.9kg
247 x 113 x120mm
0.45kg
170 x 120 x75mm
0.21kg
158 x 83 x179mm
φ8 x φ13 φ12 x φ17
4.0 Specifications
Engine
Drive
Weight
Size (L × W×H)
Displacement
Generator
Power
Maximum takeoff weight
Output voltage
Power battery
Oil Consumption
Spark plug
Fuel type
Fuel ratio
Coolant
Environment temperature
Maximum altitude
Double Cylinder Gasoline Engine
6.15kg (including spare parts)
375×290×279mm
120CC
WK-WS-150-001
7.4KW
53kg (flight near sea level and related to the power and structure of the aircraft)
DC50V
12S (Capacity ≥ 1800mAh, discharge rate ≥ 75C)
730g/kw.H (Hover 6 L/H)
NGK CM-6
95 # above unleaded gasoline + 2T synthetic lubricant (Motorway, Motul 710, etc.)
40:1
Car antifreeze engine coolant
-20℃to 40℃
4000m
Rectifier starter
Radiator
Cooling box
Radiator tube
Specifications

8
5.0 Preparations
5.1 Installation Instructions
4. Install 4 supports and fix the engine. Install the engine in the proper position of UAV,
and the default is vertical installation.
4-φ20 aperture
1. Pls. use the cross screwdriver
to loosen the air filter screw.
2. Install the air filter into the
engine intake.
3. Tighten the air filter screw with
a cross screwdriver.
Vertical Installation Diagram

9
1
1
2
2
2
2
2
2
5. Fixed radiator mounting aperture φ40
(The radiator is recommended to
be installed directly on the upper arm
under the propeller to ensure good heat
dissipation performance.)
Aperture φ3.5
6. Fixed cooling box mounting screw
aperture φ3.5
2-φ40 aperture
Rectifier Starter
Radiator
Radiator
Cooling Box
Liquid pump Engine
The cooling kit connection
diagram is as follows:
① Radiator tube φ12*φ17
②Radiator tube φ8*φ13
Blue arrow indicates the
direction of liquid circulation
Tips:

10
5.2 Connecting Lines
Connection Diagram of Rectifier Starter with Engine and Liquid Pump
Black line to green line welding (C=C)
Yellow line to yellow line welding (D=D)
blue line to blue line welding (E=E)
Rectifier Starter
Entrance
Exit
Liquid pump
Connecting liquid pump
Connecting
Spark plug
Engine

11
Connection Diagram of Rectifier Starter with
G120EFI Control Box, Power Board and Battery
Rectifier Starter
2. Sensor_2
4. PWM_IN2
3. PWM_IN1
1. Sensor_1
Starter
Starter
Power
Board
12S LiPo Battery
Capacity ≥ 1800mAh,
discharge rate ≥ 75C
DC50V battery voltage detection
1. SBUS
2. Ignition signal
3. Rotation speed signal
4. PWM_OUT
5. Servo 1
6. Servo 2
7. CDI power
Battery voltage
Battery
voltage
Control Box

12
PWM throttle control signal
input (recommended to
use the remote controller
three-speed switch)
DC-12V-IN
(DC power requirements:
12V 10A regulated power supply)
油泵
1. Sensor_1
2. Sensor_2
3. PWM_IN1
4. PWM_IN2
2.Ignition signal
5.Servo 1
3.Rotation speed signal
3.PWM_IN1
7.CDI power
Nozzle
Oil pump
1. SBUS
2. Ignition signal
3. Rotation speed signal
4. PWM_OUT
5. Servo 1
6. Servo 2
7. CDI power
Connection Diagram of G120EFI Control Box
Rectifier Starter
Engine
Oil Pump
Connecting Oil pump
Connecting
CDI power
Connecting
Ignition signal
Connecting
engine hall
Connecting
Servo
Connecting
Spark plug
Control Box

13
Engine
Silver inlet oil pipe
Yellow transparent oil return pipe
Colorless transparent oil inlet pipe
5.3 Oil circuit connection diagram
Oil Pump
Oil outlet Oil filler
Fuel Tank

14
1
2
3
4
5
1
2
3
4
5
①
②
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
5.4 Fill In Fuel And Coolant
I t is recommended to use 95 # or above unleaded gasoline and two-stroke full synthetic lubricant in
accordance with JASO FC/FD ISO-L-EGD standard. The mixing ratio is 40:1.
Please prepare the fuel using
a proportioning pot.
1. Add more than 95 #gasoline from
the big mouth to the marked area①;
Add lubricating oil from small
opening to mark②.
2. Shake blended fuel in an
inverted proportioning pot.
3. Pls.open the cover of the drone
oil kettle, inject the blended fuel
into the drone oil kettle and
tighten the cover.
Engine
Coolant
Please use car
antifreeze engine
coolant
Proportioning
pot(40:1)
Proportioning
pot(40:1)
Proportioning
pot(40:1)
Engine
Coolant
5.5 Running in
The running-in is completed before leaving
the factory and can be used directly.
4. Turn 90 degrees counter-clockwise to open the
coolant box cover, inject the special coolant for
engine into the coolant box
(about 1 liter of injection), and then turn
90 degrees clockwise to tighten the lid after filling.

15
6.0 Description of PWM Control Signal of the Remote Controller
Engine status PWM pulse width signal input of remote controller
Close engine
Engine idling
Running engine
PWM pulse width<1100us
1400us<PWM pulse width<1500us
PWM pulse width>1900us

16
Before starting, check whether the intake filter element is blocked and whether the
exhaust bolt is tightened.
The remote controller switch must be self-defined according to your remote controller.
7.0 Operation
7.1 Engine Startup
1) Put the remote controller switch to the "Engine idling" position for fire.
2) After successful lighting, turn the remote controller switch to the "Running Engine" position, and the engine
is steadily operated for one minute.
7.2 Engine Operation
1) After successful lighting, set the remote controller switch to the " Running engine " position and observe the bus
voltage (49 +1V) as normal. If it is normal, it will run steadily for about one minute to preheat the engine.
2) Push the remote controller or start the flight control program to take off.
7.3 Close Engine
1) After continuous flight, the engine system needs to be cooled. Therefore, after the landing, turn the
remote controller switch to the “Engine idling” position for 30 seconds.
2) Tu
rn the remote controller switch to the “Close engine” position and the engine system will automatically turn off.
Gasoline is a volatile, flammable and explosive liquid.
During the end of the day or during long-distance transportation, the fuel remaining in the fuel tank
should be released and stored in the oil drum to avoid danger!

17
8.0 Engine Maintenance and Warranty
8.1 Engine Maintenance
1. The engine is a high-performance two-stroke engine, so some parts lose quickly, such as bearings, ball bearings,
pistons, piston rings, spark plugs, air filters, etc. The degree of wear and tear of parts varies according to personal
usage habits, environment and temperature. We recommend that you send them back to the original factory
regularly to replace the wear and tear products.
2. Plug and air filter regularly with carburized oil cleaner.
3. The engine must periodically check whether there is leakage at the surface joints (Joints of cylinder, crankcase,
etc). Leakage will cause fuel/air ratio error, which will affect the performance of the engine or cause damage.
4. The manufacturer suggests that the user should maintain it on his own (altogether 100 hours ) regularly, and
return to the factory for full maintenance once altogether reach 300 hours. The cost of maintenance for
each manufacturer is about USD500.
5. The engine is a liquid-cooled engine. The coolant liquid tank and the liquid-cooled device must be guaranteed to
flow smoothly and the pump can run normally. (Can use car coolant liquid)
The calculation of engine warranty period is 24 months from the original purchase date. If the purchase date is not
clearly provided, the factory date shall be taken as the benchmark. During the period of quality assurance, due to
product quality problems or abrasion and damage of equipment under normal operation, as well as air filter and oil
pipeline blockage, our company is responsible for free maintenance; if artificial or improper operation, use of other
plant parts, refitting, use of inferior oil, oil mixing ratio caused by incorrect engine failure, is not within the scope of
free maintenance, according to the company's damage. Relevant components, providing paid maintenance services.
8.2 Engine Warranty

Carburetor
Cleaner
Air filter
18
1. Unscrew the fixing screw of the
air filter element and remove the
air filter element
The method of cleaning spark plug is as follows:
Carburetor
Cleaner
Spark
plugs
The method of cleaning air filter element is as follows:
2. Clean or replace air filter element
with carburetor cleaner
1. Pull the spark plug igniter hard. 2. Unscrew the spark plug with a
spark plug wrench.
3. Clean or replace spark
plugs with carburetor
cleaner

Clean or replace spark plugs with carburetor cleaner
Clean or replace spark plugs with carburetor cleaner
Reason Solution
9.0 Common Faults
9.1 Startup Difficulty
Line connection is incorrect Check the connection line and reconnect
Control circuit damage Please contact the manufacturer
Air filter has oil or dust
Air filter has oil or dust
Clean the air filter with chemical cleaner
Clean the air filter with chemical cleaner
The spark plug has carbon deposit or broken
The spark plug has carbon deposit or broken
9.2 Performance Degradation
Reason Solution
Poor fuel quality Replace the fuel
Incorrect fuel ratio Gasoline and lubricating oil are properly matched at 40:1
19

Oil Pump x1
Oil pump connection line x1
10.0 List of items
Liquid pump x1 G120EFI Control Box x1 Engine support x1
Engine x1 Cooling Box x1Radiator x2 Rectifier Starter x1
φ8*φ13 radiator tube x3m φ12*φ17 radiator tube x1m DC12V power line x1
20