Yamaha YZF-R125 Service Manual: Air induction system
1. Air induction system hose (air filter case to reed valve assembly) 2. Air induction system reed valve assembly
3. Air induction system hose (reed valve assembly to exhaust pipe)
Checking the air induction system
Air injection
The air induction system burns unburned exhaust gases by injecting fresh air (secondary air) into the exhaust port, reducing the emission of hydrocarbons. When there is negative pressure at the exhaust port, the reed valve opens, allowing secondary air to flow into the exhaust port.
The required temperature for burning the unburned exhaust gases is approximately 600 to 700 C (1112 to 1292 F).
1. Check:
- Hoses
Loose connections
Connect
properly.Cracks/damage
Replace. - Cracks/damage
Replace.
2. Check:
- Air induction system reed valve assembly operation
a. Blow air into the pipe "1" of the air induction system reed valve assembly and check that it comes out from the pipe "2".
b. Blow air into the pipe "2" of the air induction system reed valve assembly and check that it does not come out from the pipe "1".
c. If faulty, replace the air induction system reed valve assembly.
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 front and rear brake pads
The front and rear brake pads must be
checked for wear at the intervals specified
in the periodic maintenance and
lubrication chart.
Front brake pads
Remove the front brake caliper by
removing the bolts.
Bolt
Brake caliper
Lining thickness
Check each front br ...
Checking the bulbs and bulb sockets
NOTE:
Do not check any of the lights that use LEDs.
Check each bulb and bulb socket for damage or
wear, proper connections, and also for continuity
between the terminals.
Damage/wear Repair or replace
the bulb,
bulb socket or both.
Improperly connected Properly
connect.
No c ...
Replacing the headlight bulbs
The following procedure applies to the low beam
headlight bulb.
1. Remove:
Headlight bulb cover "1"
2. Remove:
Headlight bulb holder "1"
3. Remove:
Headlight bulb "1"
WARNINGSince the headlight bulb gets extremely
hot,
keep flammable products and your ...