Yamaha YZF-R125 Owners Manual: 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 represent quick and easy procedures for checking these vital systems yourself. However, should your motorcycle require any repair, take it to a Yamaha dealer, whose skilled technicians have the necessary tools, experience, and know-how to service the motorcycle properly.
Use only genuine Yamaha replacement parts. Imitation parts may look like Yamaha parts, but they are often inferior, have a shorter service life and can lead to expensive repair bills.
WARNING
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the area,
including pilot lights from water
heaters or furnaces. Gasoline or
gasoline vapors can ignite or explode,
causing severe injury or
property damage.
Rear wheel
To remove the rear wheel
WARNING
To avoid injury, securely support the
vehicle so there is no danger of it
falling over.
Loosen the axle nut.
Axle nut
Drive chain slack adjust ...
Troubleshooting charts
Starting problems or poor engine performance
Starting problems or poor engine performance
Engine overheating
WARNING
Do not remove the radiator cap when the engine and radiator are hot.
S ...
Other materials:
Disassembling the front wheel
1. Remove:
Oil seal
Wheel bearings
a. Clean the surface of the front wheel hub.
b. Remove the oil seal "1" with a flat-head
screwdriver.
NOTE:
To prevent damaging the wheel, place a rag "2"
between the screwdriver and the wheel surface.
c. Remove the wheel bearings "3" with a ge ...
Checking the crankshaft
1. Measure:
Crankshaft runout
Out of specification Replace
the crankshaft,
bearing or both.
NOTE:
Turn the crankshaft slowly.
2. Measure:
Big end side clearance
Out of specification Replace
the crankshaft.
3. Measure:
Crankshaft width
Out of specification&nbs ...
Assembling the water pump
1. Install:
Water pump seal "1"
(into the water pump housing "2")
CAUTION:Never lubricate the water pump seal
surface
with oil or grease.
NOTE:
Install the water pump seal with the special
tools.
Install the water pump seal with the special
tools to the specifi ...