Instrument and control functions
4-4
4
EAU41836
Fuel
This motorcycle has been designed to
use a premixed fuel of gasoline and 2-
stroke engine oil. Always mix the gaso-
line and oil in a clean container before
filling the fuel tank.
NOTICE
ECA15602
Always use fresh g asoline, and fill
the fuel tank with a fresh mix just be-
fore ri din g. Do not use premixe d fuel
that is more than a few hours ol d.
Mixin g g asoline an d 2-stroke en gine
oil
Pour 2-stroke engine oil into a clean
container, and then add gasoline. To
mix the fuel thoroughly, shake the con-
tainer from side to side.
NOTICE
ECA15591
Use only unlea ded g asoline. The use
of lead ed g asoline will cause severe
d amag e to internal en gine parts,
such as the piston rin gs as well as to
the exhaust system.
Your Yamaha engine has been de-
signed to use premium unleaded gas-
oline with a pump octane number
[(R+M)/2] of 91 or higher, or a research
octane number of 95 or higher. If
knocking (or pinging) occurs, use a
gasoline of a different brand.
If the recommended 2-stroke engine
oil is not available, use an equivalent
oil.
Gasohol
There are two types of gasohol: gaso-
hol containing ethanol and that con-
taining methanol. Gasohol containing
ethanol can be used if ethanol content
does not exceed 10% (E10). Gasohol
containing methanol is not recom-
mended by Yamaha because it can
cause damage to the fuel system or
vehicle performance problems.
NOTICE
ECA15552
Never mix two b rands of 2-stroke
en gine oil in the same b atch. Always
use the same type of oil to ensure
maximum en gine performance.
Shoul d it b e necessary to use a dif-
ferent oil bran d, b e sure to drain the
fuel tank an d the car buretor float
cham ber of the ol d premixe d fuel
prior to fillin g with the new type.1. 2-stroke engine oil
2. Gasoline
3. Container
Recommen ded fuel:
Premium unleaded gasoline (Gaso-
hol [E10] acceptable)
Recommen ded 2-stroke en gine oil:
See page 9-1.
Fuel tank capacity: 5.0 L (1.3 US gal, 1.1 Imp.gal)
Mixin g ratios ( gasoline to oil):
Break-in period: 15:1
After break-in: 30:1
U1SN86E0.book Page 4 Wednesday, June 7, 2017 10:21 AM
Specifications
9-1
9
Dimensions:
Overall length:1820 mm (71.7 in) (YZ85, YZ85J)
1900 mm (74.8 in) (YZ85LW, YZ85LWJ)
Overall width: 760 mm (29.9 in)
Overall height:
1125 mm (44.3 in) (YZ85, YZ85J)
1155 mm (45.5 in) (YZ85LW, YZ85LWJ)
Seat height:
840 mm (33.1 in) (YZ85, YZ85J)
875 mm (34.4 in) (YZ85LW, YZ85LWJ)
Wheelbase:
1255 mm (49.4 in) (YZ85, YZ85J)
1285 mm (50.6 in) (YZ85LW, YZ85LWJ)
Ground clearance: 330 mm (12.99 in) (YZ85, YZ85J)
360 mm (14.17 in) (YZ85LW, YZ85LWJ)
Wei ght:
Curb weight:
71 kg (157 lb) (YZ85, YZ85J)
73 kg (161 lb) (YZ85LW, YZ85LWJ)
Engine:
Combustion cycle:
2-stroke
Cooling system: Liquid cooled
Number of cylinders:
Single cylinder
Displacement: 85 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.1 : 1
Starting system: Kickstarter
Lubrication system: Premix lubrication
Engine oil:
Engine oil:
YAMALUBE 2R
Recommended brand: YAMALUBE
Transmission oil:
Type:Motor oil SAE 10W-30 type SE or higher or
Gear oil SAE 85W GL-3
Quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)
Coolant quantity:
Radiator (including all routes): 0.54 L (0.57 US qt, 0.48 Imp.qt)
Air filter:
Air filter element:Wet element
Fuel:
Recommended fuel:
Premium unleaded gasoline (Gasohol [E10]
acceptable)
Fuel tank capacity:
5.0 L (1.3 US gal, 1.1 Imp.gal)
Car buretor:
Type × quantity:
PWK28 × 1
Spark plu g(s):
Manufacturer/model:
NGK/BR10EG
Spark plug gap: 0.5–0.6 mm (0.020–0.024 in)
Clutch:
Clutch type:
Wet, multiple-disc
Drivetrain:
Primary reduction ratio:3.611 (65/18)
Final drive:
Chain
Secondary reduction ratio: 3.429 (48/14) (YZ85, YZ85J)
3.714 (52/14) (YZ85LW, YZ85LWJ)
Transmission type: Constant mesh 6-speed
Gear ratio: 1st:2.455 (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
U1SN86E0.book Page 1 Wednesday, June 7, 2017 10:21 AM
