Yamaha YZF-R125 Service Manual: Checking the spark plug
1. Remove:
- Right side cover Refer to "GENERAL CHASSIS" on page 4-1.
2. Disconnect:
- Spark plug cap
3. Remove:
- Spark plug
| CAUTION: Before removing the spark plug, blow away any dirt accumulated in the spark plug well with compressed air to prevent it from falling into the cylinder. |
4. Check:
Spark plug type
Incorrect →Change.
5. Check:
- Electrode "1" Damage/wear→ Replace the spark plug.
- Insulator "2"
Abnormal color→ Replace the spark plug.
Normal color is medium-to-light tan.
6. Clean:
- Spark plug (with a spark plug cleaner or wire brush)
7. Measure:
- Spark plug gap "a"
(with a wire thickness gauge)
Out of specification → Regap.
8. Install:
- Spark plug
NOTE:
Before installing the spark plug, clean the spark plug and gasket surface.
9. Connect:
- Spark plug cap
10.Install:
- Right side cover Refer to "GENERAL CHASSIS" on page 4-1.
Adjusting the throttle cable free play
NOTE:
Prior to adjusting the throttle cable free play, the
engine idling speed should be adjusted.
1. Check:
Throttle cable free play "a"
Out of specification →Adjust.
2. Remov ...
Checking the ignition timing
NOTE:
Prior to checking the ignition timing, check the
wiring connections of the entire ignition system.
Make sure all connections are tight and free of
corrosion.
1. Remove:
Rider seat
L ...
Other materials:
Checking the front brake lever free play
Checking the front brake lever free play
Brake lever free play
The brake lever free play should measure
2.0-5.0 mm (0.08-0.20 in) as
shown. Periodically check the brake lever
free play and, if necessary, have a
Yamaha dealer check the brake system.
WARNING
An incorrect brake le ...
Checking the ignition coil
1. Check:
Primary coil resistance
Out of specification Replace.
a. Disconnect the ignition coil connectors from
the ignition coil terminals.
b. Connect the pocket tester ( × 1)
to the ignition
coil as shown.
Positive tester probe
red/white "1"
Negative tester probe
orange ...
Lubricating the drive chain
The drive chain consists of many interacting
parts. If the drive chain is not maintained properly,
it will wear out quickly. Therefore, the drive
chain should be serviced, especially when the
vehicle is used in dusty areas.
This vehicle has a drive chain with small rubber
O-rings between eac ...