torque YAMAHA YZF-R125 2020 Owners Manual

Instrument and control functions
3-19
3
EAUE3431
Seats
Passenger seat
To remove the passenger seat
1. Remove the plastic cover.
2. Remove the nut and then slide in
forward direction to remove the
passenger seat as shown.
To install the passenger seat
1. Insert the projections on the front
of the passenger seat into the seat
holders as shown, and then place
the seat in the original position.2. Install the passenger seat by in-
stalling and tightening the nut to
the specified torque.
3. Install the plastic cover.
Rider seat
To remove the rider seat
1. Insert the key into the seat lock,
and then turn it clockwise.
2. While holding the key in the posi-
tion “2”, lift from rear of the rider
seat and pull it backward.
1. Plastic cover
1. Nut
1
ZAUE3363
ZAUE3364
1
1. Projection
2. Seat holder
Tightening torque:
Passenger seat nut:
13 N·m (1.3 kgf·m, 9.6 lb·ft)
1. Rider seat lock
2. Unlock.
ZAUE3365
1
2
2
1
ZAUE3366
UB5GE1E0.book Page 19 Monday, August 26, 2019 3:02 PM

Periodic maintenance and adjustment
6-2
6
EAU17303
Emission controls not only function to
ensure cleaner air, but are also vital to
proper engine operation and maximum
performance. In the following periodic
maintenance charts, the services relat-
ed to emissions control are grouped
separately. These services require
specialized data, knowledge, and
equipment. Maintenance, replace-
ment, or repair of the emission control
devices and systems may be per-
formed by any repair establishment or
individual that is certified (if applicable).
Yamaha dealers are trained and
equipped to perform these particular
services.
EAU85230
Tool kit
The tool kit is in the location shown.
The information included in this manual
and the tools provided in the tool kit are
intended to assist you in the perfor-
mance of preventive maintenance and
minor repairs. However, a torque
wrench and other tools are necessary
to perform certain maintenance work
correctly.
TIP
If you do not have the tools or experi-
ence required for a particular job, have
your Yamaha dealer perform it for you.
1. Tool kit
ZAUM1593
1
UB5GE1E0.book Page 2 Monday, August 26, 2019 3:02 PM

Periodic maintenance and adjustment
6-9
6
EAU19623
Checking the spark plug
The spark plug is an important engine
component, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
it should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
The porcelain insulator around the
center electrode of the spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally). If the spark plug shows a
distinctly different color, the engine
could be operating improperly. Do not
attempt to diagnose such problems
yourself. Instead, have a Yamaha deal-
er check the vehicle.
If the spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.
Before installing a spark plug, the
spark plug gap should be measured
with a wire thickness gauge and, if
necessary, adjusted to specification.Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the spark
plug threads.
TIP
If a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is 1/4…
1/2 turn past finger tight. However, the
spark plug should be tightened to the
specified torque as soon as possible.
Specified spark plug:
NGK/MR8E9
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Tightening torque:
Spark plug:
12.5 N·m (1.25 kgf·m, 9.22 lb·ft)
1
ZAUM0037
UB5GE1E0.book Page 9 Monday, August 26, 2019 3:02 PM

Periodic maintenance and adjustment
6-11
6 5. Clean the engine oil strainer with
solvent.
TIP
Skip to step 9 when only changing
the oil.
Perform steps 6–8 when replacing
the oil filter element.
6. Remove the oil filter element cover
by removing the bolts.
7. Remove and replace the oil filter
element and O-ring.8. Install the oil filter element cover
by installing the bolts, then tight-
ening them to the specified
torque.
TIP
Make sure that the O-ring is properly
seated.
9. Install the engine oil strainer, com-
pression spring, O-ring and the
engine oil drain bolt, and then
tighten it to the specified torque.
NOTICE: Before installing the
engine oil drain bolt, do not for-
get to install the O-ring, com-
pression spring, and oil strainer
in position.
[ECA10422]
10. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Strainer
5. Oil pan
1. Bolt
2. Oil filter element cover
2 3 4
51
ZAUE0672
1. Oil filter element
2. O-ring
Tightening torques:
Oil filter element cover bolt:
10 N·m (1.0 kgf·m, 7.4 lb·ft)
Tightening torques:
Engine oil drain bolt:
32 N·m (3.2 kgf·m, 24 lb·ft)
UB5GE1E0.book Page 11 Monday, August 26, 2019 3:02 PM

Periodic maintenance and adjustment
6-25
6
EAU22762
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU74253To check the drive chain slack
1. Place the motorcycle on the side-
stand.
TIP
When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
2. Shift the transmission into the
neutral position.
3. Measure the drive chain slack as
shown.
4. If the drive chain slack is incorrect,
adjust it as follows. NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle and can lead to chain slip-
page or breakage. To prevent
this from occurring, keep the
drive chain slack within the
specified limits.
[ECA10572]EAU3431B
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack.
1. Loosen the axle nut and the lock-
nut on each side of the swingarm.
2. To tighten the drive chain, turn the
drive chain slack adjusting bolt on
each side of the swingarm in di-
rection (a). To loosen the drive
chain, turn the adjusting bolt on
each side of the swingarm in di-
rection (b), and then push the rear
wheel forward.
TIP
Using the alignment marks on each
side of the swingarm, make sure that
both drive chain pullers are in the same
position for proper wheel alignment.
3. Tighten the axle nut, then the lock-
nuts to their specified torques.
1. Drive chain slack
Drive chain slack:
30.0–40.0 mm (1.18–1.57 in)
ZAUM1604
1
1. Drive chain slack adjusting bolt
2. Axle nut
3. Alignment marks
4. Locknut
Tightening torques:
Axle nut:
85 N·m (8.5 kgf·m, 63 lb·ft)
Locknut:
15 N·m (1.5 kgf·m, 11 lb·ft)
ZAUM1605
3 21
4
(b) (a)
UB5GE1E0.book Page 25 Monday, August 26, 2019 3:02 PM