Merlin
Instruction manual V1.4
Pag:
6
controlled by varying the speed of the fuel pump through an electronic controller called an ECU
(electronic control unit), that is connected to the engine trough a 3 wire digital data bus.
Installation Notes
1. The engine should be mounted using the strap mount supplied or an approved equivalent.
2. The connection cables from the engine to the ecu should be carefully routed away from the
engine intake so there is no possibility of accidental ingestion of the wire. Avoid placing the
cables close to the internal magnetic RPM sensor wich is located under the black cover at
approximately 2 o’clock when looking the engine from front with the electric connector at 12
o’clock. Cables too close can cause erratic RPM reading during startup.
3. Fuel pipe should be routed similarly clear of the intake.
4. The centre of the fuel tank should be mounted as near to the centre of gravity (CofG) of the
model as possible. This will minimize the CofG shift as the fuel is used during flight.
5. Any air ducting to the inlet of the engine must have sufficient diameter of at least twice of the
engine intake diameter.
6. If an extended exhaust duct is required, it should be of sufficient diameter and strength for
optimum engine performance. Leave a gap of 25mm between end of the engine exhaust to
exhaust tube (excluding bell mouth length)
7. Extreme care should be exercised to ensure that no foreign object, loose parts of the model or
debris are allowed to enter the compartment where the engine is installed.
We recommend testing the engine on a test stand prior airframe installation.
You should have a clear idea of how to arrange the components needed to run the engine inside
the model. The main issue is the fuel tank, you will need to arrange the CofG in the centre of the
tank and adjust the receiver and ECU batteries to achieve the correct location.
Electronic Control Unit (ECU)
The ECU is custom designed for the MERLIN engines and must not be
changed for any other, as this may result in improper control of the
engine. Your engine has been set up and run with this ECU at the
factory and the settings should be left as default. The ECU plugs into
your receiver throttle channel and is powered from the receiver
rechargeable battery. The ECU is pre-programmed and only requires
simply setting to your radio. The ecu is HV tolerant, accept voltages up to 10V in the throttle
connection.
ECU Data Terminal
The data terminal plugs into the ECU via the lead
supplied. The display can be used for starting and test
running. This socket also doubles as digital connection to
a computer.
The display can be installed permanently on
board.
