2012 YAMAHA YZ85 transmission

OPERATION AND IMPORTANT RIDING POINTS
6-2
6
EAU16671
Shifting Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.TIPTo shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.
NOTICE
ECA10260


Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long dis-
tances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.


Always use the clutch while
changing gears to avoid damag-
ing the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
EAU16690
To start out and accelerate1. Pull the clutch lever to disengage the clutch.
2. Shift the transmission into first gear.
3. Open the throttle gradually and si- multaneously release the clutch le-
ver slowly. 4. Once the motorcycle has reached
a speed high enough to change
gears, close the throttle, and at the
same time, quickly pull the clutch
lever in.
5. Shift the transmission into second gear. (Make sure not to shift the
transmission into the neutral posi-
tion.)
6. Open the throttle halfway and gradually release the clutch lever.
7. Follow the same procedure when shifting to the next gear.
EAU16710
To decelerate1. Close the throttle and apply both the front and the rear brakes to
slow the motorcycle.
2. Downshift through the gears and shift the transmission into the neu-
tral position when the motorcycle
is almost completely stopped.
1. Shift pedal
2. Neutral positionU1SN80E0.book Page 2 Thursday, June 9, 2011 11:24 AM

OPERATION AND IMPORTANT RIDING POINTS
6-3
6
EAU41503
Engine break-in
WARNING
EWA10321
Failure to properly maintain the ve-
hicle or performing maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while using the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha dealer perform
service.1. Before starting the engine, fill thefuel tank with a break-in oil-fuel
mixture as follows.
2. Start and warm up the engine. Check the operation of the controls
and the engine stop button. (See
page 4-1.)
3. Operate the motorcycle in the low- er gears at moderate throttle open-
ings for five to eight minutes. Stop
the engine and check the spark plug condition (see page 7-8); it
will show a rich condition during
break-in.
4. Allow the engine to cool. Restart the engine and operate the motor-
cycle as in the step above for five
minutes. Then, very briefly shift to
the higher gears and check the
full-throttle response. Stop the en-
gine and check the spark plug.
5. After again allowing the engine to cool, restart and run the motorcy-
cle for five more minutes. Full
throttle and the higher gears may
be used, but sustained full-throttle
operation should be avoided. Stop
the engine and check the spark
plug again.
6. Allow the engine to cool, remove the cylinder head and cylinder, and
inspect the piston and cylinder.
Remove any high spots on the pis-
ton with #600-grit wet sandpaper.
Clean all components and careful-
ly reassemble the cylinder head
and cylinder.
7. Drain the break-in oil-fuel mixture from the fuel tank and refill with the
specified mix. (See page 4-3.) 8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range. Stop
the engine and check the spark
plug condition. Restart the motor-
cycle and ride it for about 10 to 15
more minutes. The motorcycle will
now be ready to ride normally.
After the engine break-in period, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-
justments thoroughly, especially cable
and drive chain slack and loose
spokes. In addition, check all fittings
and fasteners for looseness, and tight-
en if necessary.
NOTICE
ECA15560


When any of the following parts
have been replaced, they must
be broken in.
Cylinder or crankshaft:
About one hour of break-in op-
eration is necessary.
Piston, rings or transmission
gears:
Recommended 2-stroke engine oil: See page 9-1.
Mixing ratio (gasoline to oil): 15:1
U1SN80E0.book Page 3 Thursday, June 9, 2011 11:24 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-3
7
√
5 *Cylinder 
Check cylinder for score marks or wear.
 Clean. √
 Replace. √
NO. ITEM ROUTINE
After
break-in Every
race Every
third race Every
fifth race As
required
6 *Clutch 
Check clutch housing, friction plates, clutch plates
and clutch springs for wear or damage.
 Adjust. √
√
 Replace. √
7 *Transmission 
Change the transmission oil. √
 Check transmission for damage. √
 Replace bearings. √
8 *Shift forks, guide bars,
shift cam

Replace if necessary.

Check all parts for wear and damage.
√
9 *Rotor nut
(flywheel magneto) 
Tighten. √√√
10 *Kickstarter system 
Check idle gear for damage.
√
 Replace if necessary.
11 *Exhaust system 
Check exhaust pipe and muffler for carbon deposits. √
√
 Clean. √
√
√
√
√
12
*Crankshaft 
Check crankshaft for carbon deposits and damage.
 Clean.
U1SN80E0.book Page 3 Thursday, June 9, 2011 11:24 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-9
7
To install the spark plug
1. Clean the surface of the spark plug gasket and its mating surface, 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.
TIPIf 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 speci-
fied torque as soon as possible.3. Install the spark plug cap.
EAU41448
Transmission oil The transmission must be checked for
oil leakage before each ride. If any
leakage is found, have a Yamaha deal-
er check and repair the motorcycle. In
addition, the transmission oil must be
changed at the intervals specified in the
periodic maintenance and lubrication
chart. 1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place the motorcycle on a level surface and hold it in an upright po-
sition.
3. Place an oil pan under the trans- mission case to collect the used
oil.
4. Remove the oil filler cap, the trans- mission oil drain bolt and its gasket
to drain the oil from the transmis-
sion. 5. Install the drain bolt and its new
gasket, and then tighten the bolt to
the specified torque.
6. Refill with the specified amount of the recommended transmission
oil, and then install and tighten the
oil filler cap.
Tightening torque:Spark plug:20 Nm (2.0 m ·kgf, 14 ft ·lbf)
1. Transmission oil filler cap
2. Transmission oil drain bolt
3. Gasket
Tightening torque:
Transmission oil drain bolt:
10 Nm (1.0 m ·kgf, 7.2 ft ·lbf)
Recommended transmission oil: See page 9-1.
Oil change quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)
2 1
2
3
U1SN80E0.book Page 9 Thursday, June 9, 2011 11:24 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-10
7
NOTICE
ECA10452


In order to prevent clutch slip-
page (since the transmission oil
also lubricates the clutch), do
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD ” or oils of a
higher quality than specified. In
addition, do not use oils labeled
“ ENERGY CONSERVING II ” or
higher.


Make sure that no foreign mate-
rial enters the transmission.
7. Start the engine, and then let it idle for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.
EAU20070
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.
EAUM1294
To check the coolant level1. Place the vehicle on a level sur- face and hold it in an upright posi-
tion.
2. Remove the radiator cap and check the coolant level in the radi-
ator. WARNING! Never attempt
to remove the radiator cap when
the engine is hot.
[EWA10381]
TIP

The coolant level must be checked
on a cold engine since the level
varies with engine temperature.


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.
TIPThe coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine temper-
ature.3. If the coolant is below this level, add coolant, and then install the
radiator cap. NOTICE: If coolant
1. Radiator cap
1. Correct coolant level
U1SN80E0.book Page 10 Thursday, June 9, 2011 11:24 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-22
7
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU41411
To check the drive chain slack1. Install the removable sidestand and place the motorcycle on it.TIPWhen checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.2. Shift the transmission into the neu-tral position.
3. Measure the drive chain slack as shown. 4. If the drive chain slack is incorrect,
adjust it as follows.
EAU41483
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 direc-
tion (a). To loosen the drive chain,
turn the adjusting bolt on each side
of the swingarm in direction (b),
and then push the rear wheel for-
ward. NOTICE: Improper drive
chain slack will overload the en- gine as well as other vital parts
of the motorcycle and can lead
to chain slippage or breakage.
To prevent this from occurring,
keep the drive chain slack with-
in the specified limits.
[ECA10571]
TIPUsing the alignment marks on each
drive chain puller, make sure that both
drive chain pullers are in the same po-
sition for proper wheel alignment.3. Tighten both locknuts and the axle
nut to the specified torques.
Drive chain slack:35.0 –45.0 mm (1.38 –1.77 in)
1. Drive chain slack
1. Axle nut
2. Drive chain puller
3. Locknut
4. Drive chain slack adjusting bolt
5. Alignment marks
5 4
32
U1SN80E0.book Page 22 Thursday, June 9, 2011 11:24 AM

SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1818 mm (71.6 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1821 mm (71.7 in) (ZAF)
YZ85B 1818 mm (71.6 in)
YZ85LW 1903 mm (74.9 in)
YZ85LWB 1903 mm (74.9 in)
Overall width: 758 mm (29.8 in)
Overall height:
YZ85 1161 mm (45.7 in)
YZ85B 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWB 1205 mm (47.4 in)
Seat height: YZ85 864 mm (34.0 in)
YZ85B 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWB 904 mm (35.6 in)
Wheelbase: YZ85 1255 mm (49.4 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1258 mm (49.5 in) (ZAF)
YZ85B 1255 mm (49.4 in)
YZ85LW 1286 mm (50.6 in)
YZ85LWB 1286 mm (50.6 in) Ground clearance:
YZ85 351 mm (13.82 in)
YZ85B 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWB 393 mm (15.47 in)
Weight:Curb weight:
YZ85 71 kg (157 lb)
YZ85B 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWB 73 kg (161 lb)Engine:Engine type:Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement: 84 cm ³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.20 : 1
Starting system: Kickstarter
Lubrication system: PremixEngine oil:Type:YAMALUBE 2RTransmission oil:Type:
YAMALUBE 4 (10W-40) or SAE 10W-40
Oil change quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)
Cooling system:Radiator capacity (including all routes):0.54 L (0.57 US qt, 0.48 Imp.qt)Air filter:Air filter element:Wet elementFuel:Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity: 5.0 L (1.32 US gal, 1.10 Imp.gal)Carburetor:Type × quantity:
PWK28 x 1Spark plug(s):Manufacturer/model: NGK/BR10EG
Spark plug gap:
0.5 –0.6 mm (0.020 –0.024 in)Clutch:Clutch type:
Wet, multiple-discTransmission:Primary reduction ratio:3.611 (65/18)
Final drive: Chain
U1SN80E0.book Page 1 Thursday, June 9, 2011 11:24 AM

SPECIFICATIONS
9-2
9
Secondary reduction ratio:YZ85 3.357 (47/14) (ZAF)
YZ85 3.428 (48/14)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85B 3.428 (48/14)
YZ85LW 3.714 (52/14)
YZ85LWB 3.714 (52/14)
Transmission type: Constant mesh 6-speed
Operation: Left foot operation
Gear ratio:
1st:2.454 (27/11)
2nd:
1.882 (32/17)
3rd: 1.529 (26/17)
4th: 1.294 (22/17)
5th:
1.130 (26/23)
6th: 1.000 (25/25)Chassis:Frame type:
Semi double cradle
Caster angle: YZ85 26.30 °
YZ85B 26.30 °
YZ85LW 26.90 °
YZ85LWB 26.90 ° Trail:
YZ85 88 mm (3.5 in)
YZ85B 88 mm (3.5 in)
YZ85LW 105 mm (4.2 in)
YZ85LWB 105 mm (4.2 in)
Front tire:Type:
With tube
Size: YZ85 70/100-17 40M
YZ85B 70/100-17 40M
YZ85LW 70/100-19 42M
YZ85LWB 70/100-19 42M
Manufacturer/model: YZ85 DUNLOP/D739FA (ZAF)
YZ85 DUNLOP/D756F
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85B DUNLOP/D756F
YZ85LW DUNLOP/D739FA (ZAF)
YZ85LW DUNLOP/D756F
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85LWB DUNLOP/D756FRear tire:Type:With tube
Size:
YZ85 90/100-14 49M
YZ85B 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWB 90/100-16 52M Manufacturer/model:
DUNLOP/D756
Tire air pressure (measured on cold
tires):
Front:100 kPa (1.00 kgf/cm ², 15 psi)
Rear: 100 kPa (1.00 kgf/cm ², 15 psi)
Front wheel:Wheel type:
Spoke wheel
Rim size: YZ85 17x1.40
YZ85B 17x1.40
YZ85LW 19x1.40
YZ85LWB 19x1.40Rear wheel:Wheel type:Spoke wheel
Rim size: YZ85 14x1.60
YZ85B 14x1.60
YZ85LW 16x1.85
YZ85LWB 16x1.85Front brake:Type:Single disc brake
Operation: Right hand operation
Specified brake fluid:
DOT 4Rear brake:Type:Single disc brake
U1SN80E0.book Page 2 Thursday, June 9, 2011 11:24 AM