Technical Tips; Fuel Injection Control - Yamaha F225A Service Manual

Technical tips

Fuel injection control

The F225 injects fuel simultaneously to the following cylinder pairs: #1 and #4, #2 and #5, and #3
and #6. Optimal injection timing is provided in accordance with the operating conditions of the
engine.
Starting fuel injection volume and injection timing
The injectors are actuated in sync with the standard crankshaft position signals (BTDC 70°) for cyl-
inder pairs #1 and #4, #2 and #5, and #3 and #6, respectively.
#6 #1
(Compression TDC)
CYLINDER #1 Compression
Intake Compression
CYLINDER #2
Intake
CYLINDER #3
Exhaust
CYLINDER #4
Combustion
CYLINDER #5
Combustion
CYLINDER #6
B70 B10
SIGNAL #1/4
SIGNAL #2/5
B10
SIGNAL #3/6
INJECTION #1/4
INJECTION #2/5
INJECTION #3/6
Starting injection start timing
(standard position BTDC 70
Normal fuel injection volume and injection timing
To control the actuation timing of the injectors, the injection ending timing is established by using the
top-dead-center of the intake stroke as the standard, for cylinder pairs #1 and #4, #2 and #5, and #3
and #6, respectively.
#6 #1
(Compression TDC)
Compression
CYLINDER #1
Intake Compression
CYLINDER #2
Intake
CYLINDER #3
CYLINDER #4 Exhaust
Combustion
CYLINDER #5
Combustion
CYLINDER #6
B70 B10
SIGNAL #1/4
SIGNAL #2/5
B10
SIGNAL #3/6
INJECTION #1/4
INJECTION #2/5
INJECTION #3/6
Synchronous injection completion timing
69J3D11
#2 #3
Combustion Exhaust
Combustion
Compression
Compression
Intake
Exhaust Intake
Exhaust
B70
B70 B10
B70 B10
˚ )
#2 #3
Combustion Exhaust
Combustion
Compression
Compression
Intake
Exhaust Intake
Exhaust
B70
B70 B10
B70 B10
INJF
#3/6 synchronous injection start/completion
timing setting range
Features and benefits / Technical tips
#4 #5
Intake
Exhaust Intake
Combustion Exhaust
Combustion
Compression Combustion
Intake Compression
B10
B70 B10
B70
#4 #5
Intake
Exhaust Intake
Combustion Exhaust
Combustion
Compression Combustion
Intake Compression
B10
B70 B10
B70
#6 #1 #2
Compression Expansion
Compression
Intake Compression
Exhaust
Intake
Exhaust
Combustion Exhaust
B70 B10
B70 B10
B10
S69J1390
#6 #1 #2
Compression Expansion
Compression
Intake Compression
Exhaust Intake
Exhaust
Combustion Exhaust
B70 B10
B70 B10
B10
S69J1400
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