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:
Installing the engine
1. Install:
Engine "1"
Engine mounting bolt (rear lower side) "2"
Engine mounting nut (rear lower side) "3"
Engine mounting bolt (rear upper side) "4"
Engine mounting nut (rear upper side) "5"
Engine mounting bolt (front side) "6"
Engine mounting nut (front side) "7"
NOTE:
Do not ...
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.
...
Chain drive
Removing the drive chain
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
NOTE:
Place the vehicle on a suitable stand so that the
rear wheel is elevated. ...