Yamaha YZF-R125 Service Manual: Installing the primary drive gear and balancer gears
1. Install:
- Balancer driven gear "1"
- Lock washer
- Balancer drive gear "2"
- Primary drive gear
- Washer "3"
- Balancer driven gear nut
- Primary drive gear nut
NOTE:
- Align the punch mark "a" in the balancer drive gear "2" with the punch mark "b" in the balancer driven gear "1".
- Be sure to install the washer so that its sharp edge "c" is facing the primary drive gear.
2. Tighten:
- Balancer driven gear nut "1"
- Primary drive gear nut "2"
NOTE:
- Place the aluminum plate "a" between the balancer drive gear "3" and the balancer driven gear "4", and then tighten the balancer driven gear nut.
- Place the aluminum plate "b" between the balancer drive gear "3" and the balancer driven gear "4", and then tighten the primary drive gear nut.
3. Bend the lock washer tab along a flat side of the nut.
Checking the balancer gears and primary drive gear
1. Check:
Balancer drive gear
Balancer driven gear
Cracks/damage/wear Replace.
2. Check:
Primary drive gear
Refer to "CHECKING THE PRIMARY DRIVE
GEAR" on page 5-43.
...
Crankcase
...
Other materials:
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:
...
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red terminal "1"
Negative tester probe →
gray/black terminal "2"
b. Measure the throttle pos ...
Intake air temperature sensor
1. Check:
Intake air temperature sensor resistance
Out of specification Replace
the throttle
body.
a. Connect the pocket tester ( ×
1k) to the
throttle body sensor assembly coupler as
shown.
Positive tester probe
brown/white "1"
Negative tester probe
gray/black ...