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:
Checking the front fork legs
The following procedure applies to both of the
front fork legs.
1. Check:
Inner tube
Outer tube
Bends/damage/scratches
Replace.
WARNINGDo not attempt to straighten a bent inner
tube as this may dangerously weaken it.
2. Measure:
Spring free length "a"
Out of sp ...
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 disconnecting them. Residual pressure
in the fuel lines could cause fuel to
spurt out when removing the h ...
Checking the brake fluid level
Front brake
Front brake
Minimum level mark
Rear brake
Rear brake
Minimum level mark
Insufficient brake fluid may allow air to
enter the brake system, possibly causing
it to become ineffective.
Before riding, check that the brake fluid
is above the minimum level mark an ...