2021 YAMAHA YZ85 light

Periodic maintenance an d a djustment
7-6
7
EAU84450
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
1
1
Specified spark plu g:
NGK/BR10EG
1. Spark plug gap
Spark plu g g ap:
0.5–0.6 mm (0.020–0.024 in)
UB4B82E0.book Page 6 Wednesday, March 11, 2020 1:10 PM

Periodic maintenance an d a djustment
7-8
7 6. Refill with the specified amount of
the recommended transmission
oil.
NOTICE
ECA10453
In or der to prevent clutch slip-
pa ge (since the transmission oil
also lu bricates the clutch), d o
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of a
hi gher quality than specifie d. 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 transmission.
7. Check the O-ring for damage, and replace it if necessary.
8. Install and tighten the transmis- sion oil filler cap and its O-ring.
9. 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.
EAU20071
Coolant
The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUM1296To check the coolant level1. Place the vehicle on a level sur- face and hold it in an upright posi-
tion.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
 Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.
2. Remove the radiator cap and
check the coolant level in the radi-
ator. WARNING! Never attempt
to remove the ra diator cap
when the en gine is hot.
[EWA10382]
Ti ghtenin g torque:
Transmission oil drain bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Recommen ded transmission oil:
Motor oil SAE 10W-30 type SE or
higher or Gear oil SAE 85W GL-3
Oil chan ge quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
1. Radiator cap
1
UB4B82E0.book Page 8 Wednesday, March 11, 2020 1:10 PM

Motorcycle care and stora ge
8-2
8

harsh chemicals, inclu din g
stron g aci dic wheel cleaners,
especially on spoke or mag ne-
sium wheels.
 harsh chemicals, ab rasive
cleanin g compoun ds, or wax on
matte-finished parts. Brushes
can scratch an d damag e the
matte-finish, use soft spon ge or
towel only.
 towels, spon ges, or brushes
contaminate d with a brasive
cleanin g prod ucts or stron g
chemicals such as, solvents,
g asoline, rust removers, brake
flui d, or antifreeze, etc.
Before washin g
1. Park the vehicle out of direct sun- light and allow it to cool. This will
help avoid water spots.
2. Make sure all caps, covers, elec- trical couplers and connectors are
tightly installed.
3. Cover the muffler end with a plas- tic bag and a strong rubber band.
4. Pre-soak stubborn stains like in- sects or bird droppings with a wet
towel for a few minutes.
5. Remove road grime and oil stains with a quality degreasing agent
and a plastic-bristle brush or
sponge. NOTICE: Do not use
d eg reasin g a gent on areas re-
quirin g lu brication such as
seals, gaskets, an d wheel axles.
Follow prod uct instructions.
[ECA26290]
Washing
1. Rinse off any degreaser and spray down the vehicle with a garden
hose. Use only enough pressure
to do the job. Avoid spraying wa-
ter directly into the muffler, instru-
ment panel, air inlet, or other inner
areas such as underseat storage
compartments.
2. Wash the vehicle with a quality au- tomotive-type detergent mixed
with cool water and a soft, clean
towel or sponge. Use an old tooth-
brush or plastic-bristle brush for
hard-to-reach places. NOTICE:
Use col d water if the vehicle has
b een exposed to salt. Warm wa-
ter will increase salt’s corrosive
properties.
[ECA26301]
3. For windshield-equipped vehicles: Clean the windshield with a soft
towel or sponge dampened with
water and a pH neutral detergent.
If necessary, use a high-quality
windshield cleaner or polish for
motorcycles. NOTICE: Never use
any stron g chemicals to clean
the win dshiel d. A dditionally,
some cleanin g compoun ds for
plastic may scratch the wind -
shiel d, so b e sure to test all
cleanin g prod ucts before gen-
eral application.
[ECA26310]
4. Rinse off thoroughly with clean water. Be sure to remove all deter-
gent residues, as they can be
harmful to plastic parts.
After washin g
1. Dry the vehicle with a chamois or absorbent towel, preferably mi-
crofiber terrycloth.
UB4B82E0.book Page 2 Wednesday, March 11, 2020 1:10 PM

Motorcycle care and stora ge
8-3
8 2. For drive chain-equipped models:
Dry and then lubricate the drive
chain to prevent rust.
3. Use a chrome polish to shine chrome, aluminum, and stainless
steel parts. Often the thermally in-
duced discoloring of stainless
steel exhaust systems can be re-
moved through polishing.
4. Apply a corrosion protection spray on all metal parts including
chrome or nickel-plated surfaces.
WARNING! Do not apply silicone or oil spray to seats, han d g rips,
ru bber foot pe gs or tire trea ds.
Otherwise these parts will be-
come slippery, which coul d
cause loss of control. Thor-
ou ghly clean the surfaces of
these parts before operatin g the
vehicle.
[EWA20650]
5. Treat rubber, vinyl, and unpainted plastic parts with a suitable care
product.
6. Touch up minor paint damage caused by stones, etc.
7. Wax all painted surfaces using a non-abrasive wax or use a detail
spray for motorcycles.
8. When finished cleaning, start the engine and let it idle for several
minutes to help dry any remaining
moisture.
9. If the headlight lens has fogged up, start the engine and turn on
the headlight to help remove the
moisture.
10. Let the vehicle dry completely be- fore storing or covering it.
NOTICE
ECA26320
Do not apply wax to ru bber or
unpainte d plastic parts.
 Do not use a brasive polishin g
compoun ds as they will wear
away the paint.
 Apply sprays an d wax sparin gly.
Wipe off excess afterwar ds.
WARNING
EWA20660
Contaminants left on the b rakes or
tires can cause loss of control.  Make sure there is no lu bricant
or wax on the brakes or tires.
 If necessary, wash the tires with
warm water an d a mil d d eter-
g ent.
 If necessary, clean the b rake
d iscs an d pad s with b rake
cleaner or acetone.
 Before ri din g at hi gher spee ds,
test the vehicle’s brakin g per-
formance an d cornerin g b ehav-
ior.
UB4B82E0.book Page 3 Wednesday, March 11, 2020 1:10 PM