Yamaha YZF-R125 Service Manual: Circuit diagram
4. Main fuse
5. Main switch
9. Battery
17.Engine stop switch
25.ECU (engine control unit)
30.Fuel pump
64.Ignition fuse
Fuel pump system
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Troubleshooting
If the fuel pump fails to operate.
NOTE:
Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
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Other materials:
Outline of the fi system
The main function of a fuel supply system is to provide fuel to the
combustion chamber at the optimum
air-fuel ratio in accordance with the engine operating conditions and the
atmospheric temperature. In
the conventional carburetor system, the air-fuel ratio of the mixture that is
supplied t ...
Checking the fid (fast idle solenoid)
1. Disconnect:
FID (fast idle solenoid) coupler
2. Check:
FID (fast idle solenoid) resistance
a. Disconnect the FID (fast idle solenoid) coupler
from the FID.
b. Connect the pocket tester ( × 10)
to the terminals
of the FID (fast idle solenoid).
Positive tester probe ...
Checking the camshaft sprocket and timing chain guide
1. Check:
Camshaft sprocket
More than 1/4 tooth wear "a" Replace
the
camshaft sprocket, timing chain and crankshaft
as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
Timing chain guide (exhaust side)
Damage/wear Replace.
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