Yamaha YZF-R125 Service Manual: Checking the timing chain and timing chain guide
1. Check:
- Timing chain
Damage/stiffness
Replace the
timing chain and camshaft sprocket as a set.
2. Check:
Timing chain guide (intake side)
Damage/wear Replace.
Checking the oil strainer
1. Check:
Oil strainer
Damage Replace.
Contaminants Clean with solvent.
Checking the crankcase
1. Thoroughly wash the crankcase halves in a
mild solvent.
2. Thoroughly clean all the gasket surfaces and
crankcase mating surfaces.
3. Check:
Crankcase
Cracks/damage Replace.
Oil de ...
Checking the bearings and oil seal
1. Check:
Bearings
Clean and lubricate the bearings, and then
rotate the inner race with your finger.
Rough movement Replace.
Oil seal
Damage/wear Replace.
...
Other materials:
Checking the cooling system
1. Remove:
Side covers
Upper side cowlings
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Radiator "1"
Radiator inlet hose "2"
Radiator outlet hose "3"
Coolant reservoir hose "4"
Water pump breather hose "5"
Cracks/damage → Replace.
Refer to "RADIATOR" on page 6-1 ...
Installing the primary drive gear and balancer gears
1. Install:
Balancer driven gear "1"
Lock washer
Balancer drive gear "2"
Primary drive gear
Washer "3"
Balancer driven gear nut
Primary drive gear nut
NOTE:
Align the punch mark "a" in the balancer drive
gear "2" with the punch mark "b" in the balancer
driven gear "1".
...
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur during
operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
repre ...