2021 YAMAHA TT-R50E check engine

Periodic maintenance an d a djustment
7-6
7
EAU19614
Checkin g the spark plu g
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic main-
tenance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
To remove the spark plu g
1. Remove the spark plug cap.
2. Remove the spark plug as shown, with a spark plug wrench available
at a Yamaha dealer. To check the spark plu
g
1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light
tan (the ideal color when the vehi-
cle is ridden normally).
TIP
If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for electrodeerosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
1. Spark plug cap
1. Spark plug wrench
Specified spark plu g:
NGK/CR7HSA
1. Spark plug gap
Spark plu g g ap:
0.6–0.7 mm (0.024–0.028 in)
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Periodic maintenance an d a djustment
7-7
7
To install the spark plu
g
1. Clean the surface of the spark plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
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.
3. Install the spark plug cap.
EAU49935
Engine oil
The engine oil level should be checked
before each ride. In addition, the oil
must be changed at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
To check the en gine oil level
1. Place the motorcycle on a level surface and hold it in an upright
position. A slight tilt to the side can
result in a false reading.
2. Start the engine, warm it up for several minutes, and then turn it
off.
3. Wait a few minutes until the oil set- tles, remove the engine oil filler
cap, wipe the engine oil dipstick
clean, insert it back into the oil filler
hole (without screwing it in), and
then remove it again to check the
oil level.
TIP
The engine oil should be between the
minimum and maximum level marks.
Tightening torque:
Spark plug: 13 N·m (1.3 kgf·m, 9.6 lb·ft)
1. Engine oil filler cap
2. O-ring
3. Engine oil dipstick
4. Maximum level mark
5. Minimum level mark
3
21
5
4
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Periodic maintenance an d a djustment
7-8
7 4. If the engine oil is at or below the
minimum level mark, add suffi-
cient oil of the recommended type
to raise it to the correct level.
5. Check the O-ring for damage, and replace it if necessary.
6. Insert the dipstick into the oil filler hole, and then tighten the oil filler
cap.
To chan ge the en gine oil
1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place an oil pan under the engine to collect the used oil.
3. Remove the engine oil filler cap, the engine oil drain bolt and its
gasket to drain the oil from the
crankcase.
4. Install a new gasket and the drain bolt, and then tighten the drain
bolt to the specified torque.
5. Refill with the specified amount of the recommended engine oil.
NOTICE
ECA11621
In or der to prevent clutch slip-
pa ge (since the en gine oil also
lu bricates the clutch), do not
mix any chemical add itives. Do
not use oils with a d iesel speci-
fication of “CD” or oils of a hi gh-
er quality than specified . In
a ddition, do not use oils la bele d
“ENERGY CONSERVING II” or
hi gher.
 Make sure that no forei gn mate-
rial enters the crankcase.
6. Check the O-ring for damage, and replace it if necessary.
7. Install and tighten the engine oil filler cap.
8. Start the engine, and then let it idle for several minutes while checking
it for oil leakage. If oil is leaking,
immediately turn the engine off
and check for the cause.
9. Turn the engine off, and then check the oil level and correct it if
necessary.
1. Engine oil drain bolt
2. Gasket
Tightenin g torque:
Engine oil drain bolt: 20 N·m (2.0 kgf·m, 15 lb·ft)
12
Recommen ded en gine oil:
See page 9-1.
Oil chan ge quantity:
0.80 L (0.85 US qt, 0.70 Imp.qt)
1. O-ring
1
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Periodic maintenance an d a djustment
7-12
7
EAU21363
A djustin g the en gine i dlin g
spee d
The engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
TIP
A diagnostic tachometer is needed to
make this adjustment.
1. Attach the tachometer to the
spark plug lead.
2. Start the engine and warm it up for several minutes at 1000–2000
r/min while occasionally revving it
to 4000–5000 r/min.
TIP
The engine is warm when it quickly re-
sponds to the throttle.
3. Check the engine idling speedand, if necessary, adjust it to
specification by turning the throt-
tle stop screw. To increase the en-
gine idling speed, turn the screw in
direction (a). To decrease the en-
gine idling speed, turn the screw in
direction (b).
TIP
If the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment.
1. Throttle stop screw
(a)(b)
1
En gine i dlin g spee d:
1600–1800 r/min
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Periodic maintenance an d a djustment
7-13
7
EAU21386
Checkin g the throttle grip free
play
Measure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
EAU21403
Valve clearance
The valves are an important engine
component, and since valve clearance
changes with use, they must be
checked and adjusted at the intervals
specified in the periodic maintenance
chart. Unadjusted valves can result in
improper air-fuel mixture, engine
noise, and eventually engine damage.
To prevent this from occurring, have
your Yamaha dealer check and adjust
the valve clearance at regular intervals.
TIP
This service must be performed when
the engine is cold.1. Throttle grip free play
Throttle g rip free play:
3.0–5.0 mm (0.12–0.20 in)
1
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Periodic maintenance an d a djustment
7-29
7
5. Remove the blown fuse, and then
install a new fuse of the specified
amperage. WARNING! Do not
use a fuse of a hi gher ampera ge
ratin g than recommen ded to
avoi d causin g extensive dam-
a g e to the electrical system an d
possi bly a fire.
[EWA15132]
6. Connect the battery coupler.
7. Install the battery cover by install-
ing the bolts.
8. Install the seat.
9. Turn the main switch to the on po- sition.
10. Start the engine.
11. If the fuse immediately blows again, check for a loose connec-
tion and repair. If none found,
have your Yamaha dealer check
the vehicle.
EAU75190
Supportin g the motorcycle
Since this model is not equipped with a
centerstand, use a maintenance stand
when removing the front or rear wheel,
adjusting the chain or washing the ve-
hicle, etc.
Check that the motorcycle is in a stable
and level position before starting any
maintenance.
TIP
If a suitable maintenance stand is not
available, a strong wooden box can be
used instead.
1. Battery coupler
Specified fuse:
10.0 A
1
1. Maintenance stand (for off-road motorcycle)
1
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Periodic maintenance an d a djustment
7-34
7
EAU67940
Trou bleshootin g chart
1. FuelThere is enough fuel.
There is no fuel.Supply fuel.
Check the battery.
The engine turns over
quickly.
The engine turns over
slowly.
The engine does not
start.
Check the battery.
The engine does not
start.
Check the ignition.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
Check the battery
lead connections,
and have a Yamaha
dealer charge the
battery if necessary.
2. BatteryThe battery is good.
3. IgnitionW et
Dry
There is compression.
There is no
compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.
Have a Yamaha dealer check the vehicle.
The engine does not
start.
Check the
compression.Have a Yamaha
dealer check the
vehicle.
Open the throttle
halfway and operate
the electric starter.
Remove the spark
plug and check
the electrodes.
Operate the electric
starter.
Check the fuel level
in the fuel tank.
Operate the electric
starter.
4. Compression
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Motorcycle care and stora ge
8-4
8
EAU26153
Stora ge
Short-term
Always store your motorcycle in a cool,
dry place and, if necessary, protect it
against dust with a porous cover. Be
sure the engine and the exhaust sys-
tem are cool before covering the mo-
torcycle.
NOTICE
ECA10811
 Storin g the motorcycle in a
poorly ventilated room or cover-
in g it with a tarp, while it is still
wet, will allow water an d humi d-
ity to seep in an d cause rust.
 To prevent corrosion, avoi d
d amp cellars, sta bles ( because
of the presence of ammonia)
an d areas where stron g chemi-
cals are stored .
Long-term
Before storing your motorcycle for sev-
eral months: 1. Follow all the instructions in the “Care” section of this chapter.
2. For motorcycles equipped with a fuel cock that has an “OFF” posi-
tion: Turn the fuel cock lever to
“OFF”.
3. Drain the carburetor float chamber by loosening the drain bolt; this
will prevent fuel deposits from
building up. Pour the drained fuel
into the fuel tank.
4. Fill up the fuel tank and add fuel stabilizer (if available) to prevent
the fuel tank from rusting and the
fuel from deteriorating. 5. Perform the following steps to
protect the cylinder, piston rings,
etc. from corrosion.a. Remove the spark plug cap and spark plug.
b. Pour a teaspoonful of engine oil into the spark plug bore.
c. Install the spark plug cap onto the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several times with the starter. (This will
coat the cylinder wall with oil.)
WARNING! To prevent d am-
a g e or injury from sparkin g,
make sure to groun d the
spark plu g electro des while
turnin g the en gine over.
[EWA10952]
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
6. Lubricate all control cables and the pivoting points of all levers and
pedals as well as of the side-
stand/centerstand.
7. Check and, if necessary, correct the tire air pressure, and then lift
the motorcycle so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
8. Cover the muffler outlet with a plastic bag to prevent moisture
from entering it.
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