Yamaha YZF-R125 Service Manual: Ignition system
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:
Checking the cylinder head
1. Eliminate:
Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damaging
or scratching:
Spark plug bore threads
Valve seats
2. Check:
Cylinder head
Damage/scratches Replace.
Cylinder head water jacket
Min ...
Lubrication diagrams
Clutch push lever
Main axle
Drive axle
Crankshaft
Oil filter
Oil pump assembly
Oil strainer
To cylinder head
Camshaft
Crankshaft
Main axle
Drive axle
...
Checking the drive chain
1. Measure:
15-link section "a" of the drive chain
Out of specification Replace the drive
chain.
a. Measure the length "a" between the inner
sides of the pins and the length "b" between
the outer sides of the pins on a 15-link section
of the drive chain as shown in the illustration.
...