Yamaha YZF-R125 Service Manual: Gaskets, oil seals and o-rings
1. When overhauling the engine, replace all gaskets, seals and O-rings. All gasket surfaces, oil seal lips and O-rings must be cleaned.
2. During reassembly, properly oil all mating parts and bearings and lubricate the oil seal lips with grease.
- Oil
- Lip
- Spring
- Grease
Replacement parts
Use only genuine Yamaha parts for all replacements.
Use oil and grease recommended by
Yamaha for all lubrication jobs. Other brands
may be similar in function and appearance, but
inferior in qua ...
Lock washers/plates and cotter pins
After removal, replace all lock washers/plates
"1" and cotter pins. After the bolt or nut has been
tightened to specification, bend the lock tabs
along a flat of the bolt or nut.
...
Other materials:
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester (DC 20 V) to the
rectifier/regulator coupler as shown.
Positive tester probe
red "1"
Negat ...
Checking the spark plug cap
1. Check:
Spark plug cap resistance
Out of specification Replace.
a. Remove the spark plug cap from the spark
plug lead.
b. Connect the pocket tester ( × 1k)
to the
spark plug cap as shown.
c. Measure the spark plug cap resistance. ...
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.
Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be ...