engine oil YAMAHA TTR90 2000 User Guide

3 - 4
INSP
ADJ

AIR FILTER CLEANING
1. Install:
l
Air scoop right
1

2. Install:
l
Air filter case cover
1

3. Clean:
l
Air filter element
Clean them with solvent.
NOTE:

After cleaning, remove the remaining solvent
by squeezing the element.
CAUTION:

l
Do not twist the element when squeezing
the element.
l
Leaving too much of solvent in the ele-
ment may result in poor starting.
4. Inspect:
l
Air filter element
Damage
®
Replace.
5. Apply:
l
Foam-air-filter oil or engine mixing oil
To the element.
NOTE:

Squeeze out the excess oil. Element should
be wet but not dripping.
6. Install:
l
Air filter element
1

NOTE:

Align the projection
a
on the air filter case with
the hole
b
in the air filter element.
7. Install:
l
Air filter case cover
8. Install:
l
Air scoop (right)

3 - 5
INSP
ADJ

ENGINE OIL LEVEL INSPECTION
1. Stand the motorcycle on a level surface.
NOTE:

l
When checking the oil level make sure that
the motorcycle is upright.
l
Place the motorcycle on a suitable stand.
WARNING

Never remove the oil tank cap just after
high speed operation. The heated oil could
spurt out causing danger. Wait until the oil
cools down to approximately 70 ˚C (158 ˚F).
2. Idle the engine more than 3 minutes
while keeping the motorcycle upright.
Then stop the engine and inspect the oil
level.
3. Remove:
l
Dipstick
1
4. Inspect:
l
Oil level
Oil level should be between maximum
a
and minimum
b
marks.
Oil level is low
®
Add oil to proper
level.
NOTE:

When inspecting the oil level, do not screw the
oil level gauge into the oil tank.
Insert the gauge lightly.
(For USA and CDN)
CAUTION:

l
Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
l
Do not allow foreign material to enter the
crankcase.
Recommended oil:
At –10 ˚C (10 ˚F) or higher

:
Yamalube 4 (10W30) or SAE
10W30 type SE/SF motor oil
At 5 ˚C (40 ˚F) or higher
õ
:
Yamalube 4 (20W40) or SAE
20W40 type SE/SF motor oil
010 30 50 70
90110
130
-20
-10 010
20 30 40
50

õ
˚C˚F

ENGINE OIL LEVEL INSPECTION

3 - 6
INSP
ADJ

ENGINE OIL REPLACEMENT
(Except for USA and CDN)
CAUTION:

l
Do not add any chemical additives or use
oils with a grade of CD
a or higher.
lDo not use oils labeled “ENERGY CON-
SERVING II” b or higher. Engine oil also
lubricates the clutch and additives could
cause clutch slippage.
lDo not allow foreign materials to enter the
crankcase.
5. Start the engine and let it warm up for
several minutes.
CAUTION:
When the oil tank is empty, never start the
engine.
6. Idle the engine more than 10 seconds
while keeping the motorcycle upright.
Then stop the engine and add the oil to
the maximum level.
7. Install:
lDipstick
ENGINE OIL REPLACEMENT
1. Start the engine and let it warm up for
several minutes.
2. Stop the engine and place an oil pan
under the drain bolt.
3. Remove:
lDipstick 1
lDrain bolt (with gasket) 2
Drain the crankcase of its oil.
Recommended oil:
Refer to the following chart for
selection of oils which are suited
to the atmospheric temperatures.
Recommended engine oil classi-
fication:
API STANDARD:
API “SE/SF” or higher grade
(Designed primarily for motor-
cycles)-20
-4-10
140
3010
5020
6830
8640 50
104
122¡CTemp.
¡F
10W/30
10W/40
20W/40
20W/50
a
b

3 - 7
INSP
ADJ
PILOT AIR SCREW ADJUSTMENT
4. Install:
lGasket
lDrain bolt
New
T R..20 Nm (2.0 m · kg, 14 ft · lb)
5. Fill:
lCrankcase
Oil quantity:
Total amount:
1.0 L (0.88 Imp qt, 1.06 US qt)
Periodic oil change:
0.8 L (0.70 Imp qt, 0.85 US qt)
6. Install:
lDipstick
7. Inspect:
lEngine (for oil leaks)
lOil level
Refer to “ENGINE OIL LEVEL INSPEC-
TION”.
PILOT AIR SCREW ADJUSTMENT
1. Adjust:
lPilot air screw 1
Adjusting steps:
lScrew in the pilot air screw until it is lightly
seated.
lBack out by the specified number of turns.
Pilot air screw:
1-3/4 turns out

3 - 13
INSP
ADJFRONT FORK INSPECTION/REAR SHOCK ABSORBER INSPECTION/
REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT
lTighten the wheel axle nut while pushing
down the drive chain.
T R..
Axle nut:
60 Nm (6.0 m • kg, 43 ft • lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage ® Repair
or replace.
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
lSwingarm smooth action
Abnormal noise/unsmooth action ®
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage ® Replace.
EC36M012
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
lRear shock absorber
Refer to “SWINGARM” section in the
CHAPTER 5.
3. Remove:
lSpring guide 1
NOTE:
While compressing the spring, remove the
spring guide.

4 - 14
ENGCAMSHAFT AND ROCKER ARMS
REMOVAL POINTS
Rocker arm shaft
1. Remove:
lRocker arm shafts
NOTE:
Use a slide hammer bolt 1 and weight 2 to
slide out the rocker arm shafts.
Slide hammer set:
YU-1083-A
Slide hammer bolt:
90890-01085
Weight:
90890-01084
INSPECTION
Camshaft
1. Measure:
lCam lobes length a and b
Out of specification ® Replace.
Cam lobes length limit:
Intake:
a 25.4 mm (1.00 in)
b 21.0 mm (0.83 in)
Exhaust:
a 25.26 mm (0.99 in)
b 21.017 mm (0.83 in)
ASSEMBLY AND INSTALLATION
1. Apply:
lMolybdenum disulfide oil
(onto the camshaft cam lobe)
lEngine oil
(onto the camshaft bearing)
2. Install:
lCamshaft 1

4 - 25
ENGCYLINDER AND PISTON
Piston pin
1. Inspect:
lPiston pin
Blue discoloration/grooves ®
Replace, then inspect the lubrication
system.
2. Measure:
lPiston pin-to-piston clearance
Measurement steps:
lMeasure the piston pin outside diameter
a.
If out of specification, replace the piston
pin
Outside diameter (piston pin):
12.996 ~ 13.000 mm
(0.5117 ~ 0.5118 in)
lMeasure the piston inside diameter b.
lCalculate the piston pin-to-piston clear-
ance with the following formula.
Piston pin-to-piston clearance =
Bore size (piston pin) b –
Outside diameter (piston pin) a
lIf out of specification, replace the piston.
Piston pin-to-piston clearance:
0.002 ~ 0.017 mm
(0.00008 ~ 0.00067 in)
: 0.07 mm (0.003 in)
ASSEMBLY AND INSTALLATION
Piston
1. Install:
lPiston rings
(onto the piston)
NOTE:
lBe sure to install the piston rings so that the
manufacturer’s marks or numbers are
located on the upper side of the rings.
lLubricate the piston and piston rings liberally
with engine oil.

4 - 26
ENGCYLINDER AND PISTON
2. Position:
lTop ring
l2nd ring
lOil ring
Offset the piston ring end gaps as
shown.
aTop ring end
bOil ring end (lower)
cOil ring end (upper)
d2nd ring end
3. Install:
lPiston 1
lPiston pin 2
lPiston pin clips 3
NOTE:
lApply engine oil onto the piston pin, piston
ring and piston.
lBe sure that the arrow mark a on the piston
points to the exhaust side of the engine.
lBefore installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
4. Lubricate:
lPiston
lPiston rings
lCylinder
NOTE:
Apply a liberal coating of engine oil.
New
Cylinder
1. Install:
lCylinder 1
NOTE:
Install the cylinder with one hand while com-
pressing the piston rings with the other hand.
CAUTION:
lBe careful not to damage the timing chain
damper during installation.
lPass the timing chain through the timing
chain cavity.

4 - 27
ENGCLUTCH
CLUTCH
CRANKCASE COVER (LEFT AND RIGHT)
Extent of removal:1 Crankcase cover (left) removal2 Crankcase cover (right) removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE COVER (LEFT
AND RIGHT) REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
1 Shift pedal 1
2 Drive sprocket cover 1
3 Crankcase cover (left) 1
4 Gasket 1
5 Dowel pin 2
6 Clutch adjusting screw 1
7 Kick crank 1
8 Crankcase cover (right) 1
9 Gasket 1
10 Dowel pin 2
1
2

4 - 41
ENGCRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
Extent of removal Order Part name Q’ty Remarks
CRANKCASE SEPARATION
AND CRANKSHAFT REMOVAL
Preparation for removal Seat and fuel tank
Exhaust pipe
Air filter case
Carburetor Refer to “CARBURETOR” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Engine guard
Engine assembly From the chassis.
Cylinder head Refer to “CYLINDER HEAD” section.
Cylinder and piston Refer to “CYLINDER AND PISTON” sec-
tion.
Clutch housing and clutch carrier Refer to “CLUTCH” section.
Kick axle assembly Refer to “KICK AXLE” section.