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4-20
E
FUEL
FUEL INJECTION SYSTEM
Fuel injector inspection
CAUTION:
The throttle bodies should not be disas-
sembled unnecessarily.
1. Check:
• Injector
Dirt/residue
→
Clean.
Damage
→
Replace.
2. Measure:
• Fuel injectors resistance
Out of specification
→
Replace.
3. Check the operation of the fuel injector
using the “Stationary Test” of the Yamaha
Diagnostic System.
Digital multimeter:
YU-34899-A
Digital circuit tester:
90890-03174
Fuel injector resistance:
(reference data)
11.5–12.5
Ω
at 20 °C (68 °F)
Throttle body inspection
1. Check:
• Throttle body
Cracks/damage
→
Replace the throttle
bodies.
2. Check:
• Fuel passages
Obstruction
→
Clean.
Checking steps:
• Wash the throttle body in a petroleum
based solvent.
Do not use any caustic carburetor clean-
ing solution.
• Blow out all of passages with com-
pressed air.