Yamaha YZF-R125 Service Manual: Checking the camshaft sprocket and timing chain guide
1. Check:
- Camshaft sprocket
More than 1/4 tooth wear "a"
Replace
the camshaft sprocket, timing chain and crankshaft as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
Timing chain guide (exhaust side)
Damage/wear
Replace.
Checking the cylinder head
1. Eliminate:
Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damaging
or scratching:
Spark plug bore threads
Valve seats
...
Checking the timing chain tensioner
1. Check:
Timing chain tensioner
Cracks/damage/rough movement Replace.
a. Lightly press the timing chain tensioner rod
into the timing chain tensioner housing by
hand.
NOTE:
While pressing the ...
Other materials:
Setting the normal mode
NOTE:
The engine speed, coolant temperature, and fault code, if detected, can be
displayed on the LCD of the
FI diagnostic tool when the tool is connected to the vehicle and is set to the
normal mode.
1. Set the main switch to "OFF" and the engine stop switch to "".
2. Disconnect the self- ...
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 crankshaft position sensor
1. Disconnect:
Crankshaft position sensor coupler
(from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification Replace
the crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( × 100) to the
crankshaft position sensor c ...