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:
Outline of the fi system
The main function of a fuel supply system is to provide fuel to the
combustion chamber at the optimum
air-fuel ratio in accordance with the engine operating conditions and the
atmospheric temperature. In
the conventional carburetor system, the air-fuel ratio of the mixture that is
supplied t ...
Checking the brake fluid level
1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
Make sure the vehicle is upright.
2. Check:
Brake fluid level
Below the minimum level mark "a" → Add the
recommended brake fluid to the proper level.
A. Front brake
B. Rear brake
WA ...
Installing the rear brake master cylinder
1. Install:
Copper washers "1"
Brake hose "2"
Rear brake light switch "3"
WARNINGProper brake hose routing is essential to
insure
safe vehicle operation. Refer to "CABLE
ROUTING" on page 2-33.
CAUTION:When installing the brake hose onto the
brake master ...