Rotax 915 i A series Maintenance Manual page 307

SYSTEM DESCRIPTION
The ignition voltage is distributed directly to the cylin-
ders by stationary, electronically controlled
components.
The ignition voltage is generated by four double igni-
tion coils which are situated above the spark plugs.
The ignition unit is synchronised by the signals of the
position sensors (see Chapter 76- 70-00 section
Sensors and actuators) of the crankshaft, which are
sent to the control unit (ECU) (see
section Control unit (ECU)). To determine the optimal
ignition point, the ECU uses its programmed ignition
map to adapt to the different operating states, taking
into account the signals of the knock sensor.
INTERNAL GENERATORS
See Chapter 24-20-00 section Internal generator.
DOUBLE IGNITION COILS
The four double ignition coils are fastened to the in-
take manifolds.
NOTE
The connections are labelled according to the
closest cylinder designation.
IGNITION CABLE ASSY.
The high voltage ignition cable consist of copper al-
loys for applications at high ignition temperatures.
Protection hose identification
The protection hoses of the ignition cables are la-
belled on both ends:
• On the spark plug connector side the hose is la-
belled with a number/Letter combination (1 T, 1.
B...)
• On the coil end the label marks the position of the
ignition cable on the ignition coil and on the cylin-
der head.
1, 2, 3 and 4 = cylinder
T, B = Top, Bottom
Example:
Effectivity: 915 i A Series
Edition 0/Rev. 0
BRP-Rotax
MAINTENANCE MANUAL HEAVY
Chapter 76- 10-00
Coil 1 T
Explana- Ignition coil side
tion coil 1 top
connector
NOTE
The cables are only available as complete set
(ignition cable, protection hose, ignition coil side
connector).
SPARK PLUGS
The spark plugs are not shielded but use a resist-
ance type suppressor to prevent interference.
WIRING HARNESS
All the electrical components necessary for the en-
gine are connected to the wiring harness. See
ter 76-00-00 section Engine
FUSE BOX
The fuse box contains the capacitors and all the
fuses. See Chapter 76-00-00 section Engine
management.
CRANKSHAFT POSITION SENSOR
The crankshaft position sensor sends information to
the control unit about the rotation speed and crank-
shaft position.
Cyl. 2 B
Cylinder head 2
bottom spark
plug
Chap-
management.
74–20–00
Page 5
August 01 2018