YAMAHA YZ85 2007 Service Manual

OPERATION AND IMPORTANT RIDING POINTS
5-3
5
EAU41502
Engine break-in 1. Before starting the engine, fill the
fuel 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 3-1.)
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 6-8); 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 motor-
cycle 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.
WARNING
EWA10320
If you are not familiar with mainte-
nance work, have a Yamaha dealerdo it for you.
7. Drain the break-in oil-fuel mixture
from the fuel tank and refill with the
specified mix. (See page 3-3.)
8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range. Stop
the engine and check the sparkplug 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.
CAUTION:
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:
These parts require about 30
minutes of break-in operation at
half-throttle or less. Observe the
condition of the engine carefully
during operation.
Recommended 2-stroke engine oil:
See page 8-1.
Mixing ratio (gasoline to oil):
15:1
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OPERATION AND IMPORTANT RIDING POINTS
5-4
5


If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-cle.
EAU17190
Parking When parking, stop the engine, and
then turn the fuel cock lever to “OFF”.
WARNING
EWA10310


Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them.


Do not park on a slope or on soft
ground, otherwise the vehiclemay overturn.
U5PA85E0.book Page 4 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-1
6
EAU17240
Safety is an obligation of the owner. Pe-
riodic inspection, adjustment and lubri-
cation will keep your vehicle in the
safest and most efficient condition pos-
sible. The most important points of in-
spection, adjustment, and lubrication
are explained on the following pages.
The intervals given in the periodic
maintenance and lubrication chart
should be simply considered as a gen-
eral guide under normal riding condi-
tions. However, DEPENDING ON THE
WEATHER, TERRAIN, GEOGRAPHI-
CAL LOCATION, AND INDIVIDUAL
USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORT-
ENED.
WARNING
EWA10320
If you are not familiar with mainte-
nance work, have a Yamaha dealerdo it for you.
U5PA85E0.book Page 1 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-2
6
EAU41794
Periodic maintenance and lubrication chart The following chart is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as weather,
terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals. If you are in
doubt as to what intervals to follow in maintaining and lubricating your motorcycle, consult your Yamaha dealer.NOTE:

From the seventh race, repeat the maintenance intervals starting from “Every race”.


Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technicalskills.
NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
1
*PistonCheck piston for carbon deposits and cracks or dam-
age.
Clean.√
√ √
Replace.
√ √
2*
Piston ringsCheck piston ring end gap and rings for damage.√
Replace.
3*Piston pin and small
end bearingCheck piston pin and small end bearing for damage.√√√
Replace.√
√ 4*Cylinder headCheck cylinder head for carbon deposits.
Clean.√
√ √
Check cylinder head gasket for damage.
Replace cylinder head gasket. Tighten cylinder head bolts if necessary.√
U5PA85E0.book Page 2 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-3
6
√
5
*CylinderCheck cylinder for score marks or wear.
Clean.√
Replace.√ NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
6*ClutchCheck clutch housing, friction plates, clutch plates
and clutch springs for wear or damage.
Adjust.√ √
Replace.√
7*TransmissionChange 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 systemCheck idle gear for damage.
√
Replace if necessary.
11*Exhaust system Check exhaust pipe and muffler for carbon deposits.√ √
Clean.√
√
√ √
√ 12*CrankshaftCheck crankshaft for carbon deposits and damage.
Clean.
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-4
6
NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
√
√
√ 13*CarburetorCheck carburetor settings and for obstructions.√
Adjust and clean.√
14 Spark plugCheck condition.
Clean and regap.√
Replace.√
15 Drive chainCheck chain slack, alignment and condition.
Adjust and thoroughly lubricate chain with Yamaha
chain and cable lube or equivalent.√
√
√
√ √
Replace.√
16*Cooling systemCheck coolant level and for leakage.√ √
Check hoses for cracks or damage.√
Check radiator cap spring operation.√
Change coolant. Every 2 years√
17*Chassis fastenersCheck all chassis fitting and fasteners.
Correct or tighten if necessary.√
18*Air filter elementClean.
√
Replace.√
19*FrameClean and check for damage.√
20*Fuel line Clean and check for leakage.√√
U5PA85E0.book Page 4 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-5
6
√ √
21*BrakesAdjust lever position and pedal height.
Lubricate pivot points.
Check brake disk surface.
Check fluid level and for leakage.
Tighten brake disk bolts, caliper bolts, master cylinder
bolts and union bolts.√
Replace brake pads.√
Replace brake fluid. Every year√
22*Front fork
Replace oil seals. Replace fork oil. 
Clean dust seal and lubricate with lithium-soap-based
grease.
Adjust if necessary. Check operation and for oil leakage.
√
√√
√ NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
√ √
√
23*Shock absorber assem-
blyCheck operation and adjust.
Tighten if necessary.
Lubricate with molybdenum disulfide grease.√(After
washing
the
motorcycle
or riding in
the rain)
U5PA85E0.book Page 5 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-6
6
EAU42010
NOTE:

Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
√ √√
√ 24*Drive chain roller and
support guideReplace if necessary. Check for wear or damage.
√
25*Rear suspensionCheck operation and tighten if necessary.
Lubricate with molybdenum disulfide grease.
NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
√
√
√
√ √ √
√ √√ √
√
√
√
√
√ 26*Steering headCheck operation, free play, and tighten if necessary.
Clean and lubricate with lithium-soap-based grease.
Replace bearings.
27*Tires and wheelsCheck tire air pressure, wheel runout, spokes for
looseness, and tires for wear.
Tighten sprocket bolts if necessary.
Check wheel bearings for looseness.
Lubricate wheel bearings with lithium-soap-based
grease.
Replace wheel bearings.
28*Moving parts and ca-
blesLubricate.
29*Throttle grip housing
and cableCheck operation and free play.
Adjust the throttle cable free play if necessary.
Lubricate the throttle grip housing and cable.
U5PA85E0.book Page 6 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
6 Every two years replace the internal components of the brake master cylinders and calipers, and change the brake
fluid.
Replace the brake hoses every four years and if cracked or damaged.
U5PA85E0.book Page 7 Thursday, April 13, 2006 3:06 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-8
6
EAU19612
Checking the spark plug 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 mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
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 plug
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 vehicle is
ridden normally).
NOTE:
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 checkthe vehicle.2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
1. Spark plug cap
1. Spark plug wrench
Specified spark plug:
NGK/BR10EG1. Spark plug gapSpark plug gap:
0.5–0.6 mm (0.020–0.024 in)
U5PA85E0.book Page 8 Thursday, April 13, 2006 3:06 PM