Yamaha 2002 TDM900, Service Manual

Page: 20 / 475

1-9
FEATURES
GEN
INFO
A Fuel
4
Needle
5
Inject
6
Flange
1
Coil
2
Core
3
Spacer
Fuel injector
Upon receiving injection signals from the ECU, the fuel injector injects fuel. In the normal state, the core
is pressed downward by the force of the spring, as illustrated. The needle that is integrated with the
bottom of the core keeps the fuel passage closed.
When the current flows to the coil in accordance with the signal from the ECU, the core is drawn up-
ward, allowing the flange that is integrated with the needle to move to the spacer. Since the distance of
the movement of the needle is thus kept constant, the opening area of the fuel passage also becomes
constant. Because the pressure difference of the fuel to the intake manifold pressure is kept constant
by the pressure regulator, the fuel volume varies in proportion to the length of time the coil is energized.
The injector that has been recently adopted has a four-hole type injection orifice that enhances the
atomization of fuel and improves combustion efficiency.