Yamaha YZ125 2016, Owner'S Service Manual

Page: 52 / 166

3-9
ENGINE
Never attempt to remove the oil
check bolt just after high speed
operation. The heated oil could
spout out, causing danger. Wait
until the oil cools down.
Oil flows out → Oil level is correct.
Oil does not flow out
→
Oil level is
low. Add transmission oil until oil
flows out.
c. Inspect the gasket (oil check bolt),
replace if damaged.
d. Tighten the oil check bolt.
CHANGING THE TRANSMISSION
OIL
1. Start the engine and warm it up
for several minutes and wait for
five minute.
2. Place the machine on a level
place and hold it on upright posi-
tion by placing the suitable stand
under the engine.
3. Place a suitable container under
the engine.
4. Remove:
• Oil drain bolt "1"
• Oil filler cap "2"
Drain the transmission oil.
5. Install:
• Aluminum washer
• Oil drain bolt "1"
6. Fill:
• Transmission oil
7. Check:
• Oil leakage
8. Check:
• Transmission oil level
9. Install:
• Oil filler cap "2"
ADJUSTING THE PILOT AIR
SCREW
1. Adjust:
• Pilot air screw "1"
Adjustment steps:
a. Screw in the pilot air screw until it
is lightly seated.
b. Back out by the specified number
of turns.
ADJUSTING THE ENGINE IDLING
SPEED
1. Start the engine and thoroughly
warm it up.
2. Adjust:
• Engine idling speed
Adjustment steps:
a. Loosen the locknut "1".
b. Turn the throttle stop screw "2"
until the engine runs at the lowest
possible speed.
c. Tighten the locknut.
CHECKING THE EXHAUST PIPE
1. Inspect:
• O-ring "1"
Damage
→
Replace.
Install the O-rings with their de-
pressed "a" facing outward.
Recommended brand:
YAMALUBE
Recommended engine
oil type
SAE10W-40
Recommended engine
oil grade
API service SG type or
higher
JASO standard MA
Oil check bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil drain bolt:
20 Nm (2.0 m•kg, 14
ft•lb)
Recommended brand:
YAMALUBE
Recommended engine
oil type
SAE10W-40
Recommended engine
oil grade
API service SG type or
higher
JASO standard MA
Oil capacity (periodic oil
change):
0.66 L (0.58 Imp qt, 0.70
US qt)
Pilot air screw:
2-1/4 turns out
To increase idle speed
→
Turn the
throttle stop screw "2" in.
To decrease idle speed
→
Turn the
throttle stop screw "2" out.