Yamaha YZF-R125 Service Manual: Troubleshooting
The ignition system fails to operate (no spark or intermittent spark).
NOTE:
- Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Right side cover
4. Left side panel
5. Left upper side cowling
Circuit diagram
2. Crankshaft position sensor
4. Main fuse
5. Main switch
8. Sidestand switch
9. Battery
17.Engine stop switch
23.Lean angle sensor
25.ECU (engine control unit)
26.Ignition coil
27.Spark ...
Other materials:
Installing the throttle body
1. Install:
Throttle body joint clamps
NOTE:
Align the projections "a" on the throttle body joint
with the slot "b" in each throttle body joint clamp.
2. Install:
Throttle body joint
NOTE:
Align the projection "a" on the throttle body joint
with the slot "b" in the intake mani ...
Checking the spark plug
1. Remove:
Right side cover
Refer to "GENERAL CHASSIS" on page 4-1.
2. Disconnect:
Spark plug cap
3. Remove:
Spark plug
CAUTION:Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from falling
...
Installing the cylinder head
1. Install:
Cylinder head
NOTE:
Pass the timing chain through the timing chain
cavity.
2. Tighten:
Cylinder head bolts "1"
Cylinder head bolts "2"
NOTE:
Lubricate the cylinder head bolts and washers
with engine oil.
Tighten the cylinder head bolts in the proper
tighten ...