Ignition System - Yamaha FT50C Service Manual

GEN
INFO

Ignition system

In order to determine the optimal ignition timing that is necessary for the proper operation of the
engine, the built-in microcomputer in the CDI unit detects the signals from various types of sensors
and controls the ignition timing in accordance with a control map that is based on those signals. The
microcomputer also effects controls to protect the engine against overheating, over-revolution, and
oil pressure drops, as well as to control warning devices.
2
1
1 Pulser coil
2 Flywheel
3 Charge coil
4 CDI unit
5 Microcomputer
Flywheel
Three protrusions for the pulser coil are provided along the periphery of the flywheel. The purpose
of these protrusions is for detecting the engine speed. Two of them are used for ignition signals, and
one is used for identifying the cylinders, and these signals are transmitted to the microcomputer.
1-15
General information
3
8
9
4
5
6 Ignition coils #1 and #4
7 Ignition coils #2 and #3
8 Oil pressure switch
9 Thermoswitch
6
7
S62Y1310
62Y5A11