Intake System - Yamaha F150A Service Manual

GEN
INFO

Intake system

Multi-point, group fuel injection with four separate throttle valves is adopted for the intake system.
Intake air volume is calculated according to engine speed, Intake air pressure, and throttle position,
and then the fuel injection volume is determined by the intake air volume to obtain a precise air and
fuel ratio under all operating conditions.
The cylinders are grouped, #1/#4 and #2/#3. Fuel is injected twice during each full cycle of each cyl-
inder, once during the exhaust stroke and once during the compression stroke. Fuel is injected dur-
ing the compression stroke of the #1 cylinder and the exhaust stroke of the #4 cylinder and during
the exhaust stroke of the #1 cylinder and the compression stroke of the #4 cylinder. The same
occurs during the compression and exhaust strokes of the #2 and #3 cylinders.
This allows a simpler fuel injection control system.
1
#1 cylinder
#3 cylinder
#4 cylinder
#2 cylinder
1 Four separate throttle valve
1-9
General information
BTDC10
Compression
Intake
Exhaust
Combustion
Initial injection timing
Combustion Exhaust
Compression Combustion
Intake Compression
Exhaust Intake
Intake
Exhaust
Combustion
Compression
S63P1120
63P3F11