Yamaha YZF-R125 Service Manual: Installing the valves
The following procedure applies to all of the valves and related components.
1. Deburr:
- Valve stem end (with an oil stone)
2. Lubricate:
- Valve stem "1"
- Valve stem seal "2"
(with the recommended lubricant)
3. Install:
- Lower spring seat "1"
- Valve stem seal "2"
- Valve "3"
- Valve spring "4"
- Upper spring seat "5" (into the cylinder head)
NOTE:
- Make sure each valve is installed in its original place.
- Install the valve springs with the larger pitch "a" facing up.
b. Smaller pitch
4. Install:
- Valve cotters "1"
NOTE:
Install the valve cotters by compressing the
valve spring with the valve spring compressor
and the valve spring compressor attachment "2".
5. To secure the valve cotters onto the valve stem, lightly tap the valve tip with a soft-face hammer.
| CAUTION: Hitting the valve tip with excessive force could damage the valve. |
Checking the valve springs
The following procedure applies to all of the
valve springs.
1. Measure:
Valve spring free length "a"
Out of specification Replace the valve
spring.
2. Measure:
Compressed valve ...
Other materials:
Installing the front fork legs
The following procedure applies to both of the
front fork legs.
1. Install:
Front fork leg
Temporarily tighten the upper and lower
bracket pinch bolts.
NOTE:
Make sure the inner tube end position "a" is 24.5
mm (0.96 in) from the top of the upper bracket.
2. Tighten:
Lower br ...
Assembling the rear brake caliper
WARNING
Before installation, all internal brake components
should be cleaned and lubricated
with clean or new brake fluid.
Never use solvents on internal brake components
as they will cause the brake caliper
piston dust seal and piston seal to swell
and distort.
...
Measuring the compression pressure
NOTE:
Insufficient compression pressure will result in a
loss of performance.
1. Measure:
Valve clearance
Out of specification →Adjust.
Refer to "ADJUSTING THE VALVE CLEARANCE"
on page 3-3.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Remove:
...