Page 35 of 82
![YAMAHA TTR90 2007 Owners Manual OPERATION AND IMPORTANT RIDING POINTS
5-2
5
EAU40090
Starting and warming up a
cold engine [TT-R90E(W)]1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engi YAMAHA TTR90 2007 Owners Manual OPERATION AND IMPORTANT RIDING POINTS
5-2
5
EAU40090
Starting and warming up a
cold engine [TT-R90E(W)]1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engi](/manual-img/51/51682/w960_51682-34.png)
OPERATION AND IMPORTANT RIDING POINTS
5-2
5
EAU40090
Starting and warming up a
cold engine [TT-R90E(W)]1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engine stop switch is
set to “”.
3. Shift the transmission into the neu-
tral position.
WARNING
EWA14410
Be sure to shift the transmis-
sion into neutral before starting
the engine.
Never ride with the sidestanddown.
4. Turn the starter (choke) on and
completely close the throttle. (See
page 3-6.)
5. Start the engine by pushing the
start switch.
6. After starting the engine, move the
starter (choke) back halfway.
CAUTION:
ECA11130
For maximum engine life, always
warm the engine up before starting
off. Never accelerate hard when theengine is cold!
7. When the engine is warm, turn the
starter (choke) off.NOTE:The engine is warm when it responds
normally to the throttle with the starter(choke) turned off.
EAU16640
Starting a warm engine Follow the same procedure as for start-
ing a cold engine with the exception
that the starter (choke) is not required
when the engine is warm.
U3P281E0.book Page 2 Monday, April 17, 2006 11:26 AM
Page 36 of 82

OPERATION AND IMPORTANT RIDING POINTS
5-3
5
EAU39901
Shifting This motorcycle has a 3-speed trans-
mission with a centrifugal, automatic
clutch. 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.NOTE:To shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of itstravel.
CAUTION:
ECA15441
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 release the throttle grip
before changing gears to avoid
damaging the engine, transmis-
sion, and drive train, which are
not designed to withstand the
shock of shifting when the throt-tle grip is open.
EAU39910
To start out and accelerate
1. Close the throttle.
2. Shift into first gear and release the
shift pedal.
CAUTION:
ECA15460
Always close the throttle before
shifting gears, otherwise damage to
the engine and drive train may re-sult.
3. Open the throttle gradually.
4. Once the motorcycle has reached
a speed high enough to change
gears, close the throttle.
5. Shift into second gear and release
the shift pedal.
6. Open the throttle gradually.
7. Follow the same procedure when
shifting to the next higher gear.
EAU16710
To decelerate
1. 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 positionU3P281E0.book Page 3 Monday, April 17, 2006 11:26 AM
Page 37 of 82

OPERATION AND IMPORTANT RIDING POINTS
5-4
5
EAU39920
Engine break-in There is never a more important period
in the life of your engine than the first 5
hours of riding. It is also important to ac-
custom the rider to the motorcycle dur-
ing this time. Please read the following
information carefully.
Since the engine is brand new, do not
put an excessive load on it for the first 5
hours of operation. The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that might
result in engine overheating must be
avoided. However, momentary full-
throttle operation under load (i.e., two
to three seconds maximum) does not
harm the engine. Each full-throttle ac-
celeration should be followed with a
substantial rest period for the engine.
To allow the engine to cool down from
the temporary buildup of heat, cruise at
a lower engine speed.
After the first 5 hours of operation, 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:
ECA10270
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealercheck the vehicle.
EAU17190
Parking [TT-R90(W)]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.
U3P281E0.book Page 4 Monday, April 17, 2006 11:26 AM
Page 38 of 82
OPERATION AND IMPORTANT RIDING POINTS
5-5
5
EAU17170
Parking [TT-R90E(W)]When parking, stop the engine, remove
the key from the main switch, 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.
U3P281E0.book Page 5 Monday, April 17, 2006 11:26 AM
Page 41 of 82

PERIODIC MAINTENANCE AND MINOR REPAIR
6-3
6
EAU39943
Periodic maintenance chart for the emission control system NOTE:
From 7000 km (4200 mi) or 18 months, repeat the maintenance intervals starting from 3000 km (1800 mi) or 6 months.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technicalskills.
No. ITEM CHECKS AND MAINTENANCE JOBSINITIAL ODOMETER READINGS
1000 km
(600 mi) or
1 month or
30 hours3000 km
(1800 mi) or
6 months or
90 hours5000 km
(3000 mi) or
12 months or
150 hours
1*Fuel lineCheck fuel hoses for cracks or damage.
Replace if necessary.√√
2 Spark plugCheck condition.
Adjust gap and clean.√√
3*Valve clearanceCheck and adjust valve clearance when engine is cold.√
4*Air filter elementClean with solvent.
Replace if necessary.√√
5*Crankcase breather sys-
temCheck ventilation hose for cracks or damage and drain
any deposits.
Replace if necessary.√√√
6*CarburetorCheck engine idling speed and starter operation.
Adjust if necessary.√√√
7 Exhaust systemCheck for leakage.
Tighten if necessary.
Replace gasket(s) if necessary.√√
8 Engine oilChange (warm engine before draining).√√√
U3P281E0.book Page 3 Monday, April 17, 2006 11:26 AM
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-5
6
EAU40000
NOTE:The air filter needs more frequent service if you are riding in unusually wet or dusty areas.10*Chassis fastenersCheck all chassis fitting and fasteners.
Correct if necessary.√√√
11 Brake lever pivot shaftApply lithium-soap-based grease (all-purpose grease)
lightly.√√
12 Brake pedal pivot shaftApply lithium-soap-based grease (all-purpose grease)
lightly.√√
13 Sidestand pivotCheck operation.
Apply lithium-soap-based grease (all-purpose grease)
lightly.√√
14*Spark arresterClean.√
15*Front forkCheck operation and for grease leakage.
Replace if necessary.√√
16*Shock absorber assem-
blyCheck operation and for oil leakage.
Replace if necessary.√
17*Control cablesApply Yamaha chain and cable lube or engine oil 10W-30
thoroughly.√√√
18*Throttle grip housing and
cableCheck operation and free play.
Adjust the throttle cable free play if necessary.
Lubricate the throttle grip housing and cable.√√√ No. ITEM CHECKS AND MAINTENANCE JOBSINITIAL ODOMETER READINGS
1000 km
(600 mi) or
1 month or
30 hours3000 km
(1800 mi) or
6 months or
90 hours5000 km
(3000 mi) or
12 months or
150 hours
U3P281E0.book Page 5 Monday, April 17, 2006 11:26 AM
Page 45 of 82

PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
6
EAU19603
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 the spark plug wrench includ-
ed in the owner’s tool kit.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/CR6HSA
DENSO/U20FSR-U
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
U3P281E0.book Page 7 Monday, April 17, 2006 11:26 AM
Page 46 of 82

PERIODIC MAINTENANCE AND MINOR REPAIR
6-8
62. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:
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 speci-fied torque as soon as possible.
4. Install the spark plug cap.
EAU39840
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 engine oil level
1. Place the motorcycle on a level
surface and hold it in an upright po-
sition.NOTE:Make sure that the motorcycle is posi-
tioned straight up when checking the oil
level. A slight tilt to the side can result ina 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 oil filler cap, wipe
the dipstick clean, insert it back
into the oil filler hole (without
screwing it in), and then remove it
again to check the oil level.
NOTE:
The engine oil should be between theminimum and maximum level marks.
4. If the engine oil is at or below the
minimum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
5. Insert the dipstick into the oil filler
hole, and then tighten the oil filler
cap.
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
1. Engine oil filler cap
2. Dipstick
3. Maximum level mark
4. Minimum level mark
U3P281E0.book Page 8 Monday, April 17, 2006 11:26 AM