Yamaha YZF-R125 Service Manual: Checking the throttle body
1. Check:
- Throttle body
Cracks/damage
Replace the
throttle body.
2. Check:
- Fuel passages
Obstruction Clean.
a. Wash the throttle body in a petroleum-based solvent.
Do not use any caustic carburetor cleaning solution.
b. Blow out all of the passages with compressed air.
Removing the throttle body
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Disconnect:
Fuel hose
WARNINGCover the fuel hose connections with a
cloth
when disconnecti ...
Installing the throttle body
1. Install:
Throttle body joint clamps
NOTE:
Align the projections "a" on the throttle body joint
with the slot "b" in each throttle body joint clamp.
2. Install:
Throttle body joint ...
Other materials:
Checking the cylinder head breather hose
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Cylinder head breather hose "1"
Cracks/damage → Replace.
Loose connection → Connect properly.
CAUTION:Make sure the cylinder head
breather hose is
routed correctly.
...
Checking the valves and valve guides
The following procedure applies to all of the
valves and valve guides.
1. Measure:
Valve-stem-to-valve-guide clearance
Out of specification Replace the
valve
guide.
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter "a" -
Valve stem diameter "b"
2. Replace:
...
Bearings and oil seals
Install bearings "1" and oil seals "2" so that the
manufacturer's marks or numbers are visible.
When installing oil seals "1", lubricate the oil seal
lips with a light coat of lithium-soap-based
grease. Oil bearings liberally when installing, if
appropriate.
CAUTION:Do not spin th ...