clock YAMAHA TTR90 2001 Owners Manual

1 - 11
GEN
INFO

CONTROL FUNCTIONS/FUEL
FUEL TANK CAP
Remove the fuel tank cap
1 by turning
counter-clockwise.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine.
FUEL
Use regular gasoline. Always use fresh, name
brand gasoline.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine. Do not fill the fuel
tank above the bottom of the filler tube 1
as shown in the illustration or it may over-
flow when the fuel heats up later and
expands.
aFuel level
Recommended fuel:
For USA:
Unleaded fuel
For CDN and EUROPE:
Rgular unleaded gasoline
For AUS:
Unleaded fuel only
For NZ:
Regular gasoline
Fuel tank capacity:
Total:
4.2 L (0.92 lmp gal, 1.11 US gal)
Reserve:
0.5 L (0.11 lmp gal, 0.13 US gal)

SPEC

2 - 6
Stem runout limit ---- 0.02 mm
(0.0008 in)
Valve seat width IN 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
EX 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
Valve spring:
Free length IN 28.32 mm (1.11 in) 26.9 mm
(1.06 in)
EX 28.32 mm (1.11 in) 26.9 mm
(1.06 in)
Set length (valve closed) IN 24.2 mm (0.95 in) ----
EX 24.2 mm (0.95 in) ----
Compressed pressure
(installed) IN 90.4 ~ 104.1 N
(9.2 ~ 10.6 kg, 20.32 ~ 23.40 lb)----
EX 90.4 ~ 104.1 N
(9.2 ~ 10.6 kg, 20.32 ~ 23.40 lb)----
Tilt limit IN ---- 2.5˚/1.2 mm
(2.5˚/0.05 in)
EX ---- 2.5˚/1.2 mm
(2.5˚/0.05 in)
Direction of winding
(top view) IN Clockwise ----
EX Clockwise ---- Item Standard Limit
*

MAINTENANCE SPECIFICATIONS

3 - 9
INSP
ADJ
VALVE CLEARANCE ADJUSTMENT
4. Check:
lValve clearance
Out of specification ® Adjust.
5. Adjust:
lValve clearance
Valve clearance (cold):
Intake valve:
0.05 ~ 0.09 mm
(0.0020 ~ 0.0035 in)
Exhaust valve:
0.08 ~ 0.12 mm
(0.031 ~ 0.047 in)
Checking steps:
lTurn the crankshaft counterclockwise with
a wrench.
lAlign the T.D.C. mark a on the rotor with
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.
lMeasure the valve clearance using a
feeler gauge 1.
Out of specification ® Adjust clearance.
Adjustment steps:
lLoosen the locknut 1.
lTurn the adjuster 3 in or out with the
valve adjusting tool 2 until specified clear-
ance is obtained.
Turning in ®
Valve clearance is decreased.
Turning out ®
Valve clearance is increased.
Valve adjusting tool:
YM-8035/90890-01311
lHold the adjuster to prevent it from moving
and tighten the locknut.
lMeasure the valve clearance.
lIf the clearance is incorrect, repeat above
steps until specified clearance is obtained.
1
12 3
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)

3 - 12
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
lDrive chain slack a
In the center between the drive axle
and rear wheel axle.
Out of specification ® Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 53 mm (1.6 ~ 2.1 in)
3. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the wheel axle nut 1.
lAdjust chain slack by turning the adjusters
2.
To tighten ®Turn adjuster 2 clockwise.
To loosen ®Turn adjuster 2 counter-
clockwise and push wheel
forward.
lTurn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
12 a
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.

4 - 10
ENGCYLINDER HEAD
REMOVAL POINTS
Cylinder head
1.Align:
l“I” mark
(with stationary pointer)
Checking steps:
lTurn the crankshaft counterclockwise with
a wrench.
lAlign the “I” mark a on the rotor with the
stationary pointer b on the crankcase
cover. When the “I” mark is aligned with
the stationary pointer, the piston is at the
Top Dead Center (T.D.C.).
NOTE:
lIn order to be sure that the piston is at Top
Dead Center, the match mark c on the
camshaft sprocket must align with the sta-
tionary pointer d on the cylinder head as
shown in the illustration.
lIf there is no valve clearance, rotate the
crankshaft counterclockwise one turn.
2.Loosen:
lCamshaft sprocket bolt 1
3.Remove:
lTiming chain tensioner
lCamshaft sprocket 2
NOTE:
lFasten a safety wire to the timing chain 3 to
prevent it from falling into the crankcase.
lRemove the bolt 1 while holding the rotor
nut with a wrench.

4 - 11
ENG

CYLINDER HEAD
4. Remove:
l
Cylinder head
NOTE:

l
Loosen the bolts and nuts in their proper
loosening sequence.
l
Start by loosening each bolt and nut 1/2 turn
until all are loose.
ASSEMBLY AND INSTALLATION
1. Install:
l
Cylinder head
2. Tighten:
l
Nuts
l
Bolts
NOTE:

l
Apply the engine oil on the contact surfaces
of the nuts, bolts and copper washers.
l
Follow the numerical order shown in the illus-
tration. Tighten the bolts and nuts in two
stages.
T R..22 Nm (2.2 m · kg, 16 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

3. Install:
l
Camshaft sprocket
1

Installation steps:
l
Turn the crankshaft counterclockwise until
the “I” mark
a
on the rotor is aligned with
the stationary pointer
b
on the crankcase
cover.
l
Align the “I” mark
c
on the camshaft
sprocket with the stationary pointer
d
on
the cylinder head.
l
Fit the timing chain
2
onto camshaft
sprocket and install the camshaft sprocket
on the camshaft.
NOTE:
When installing the camshaft sprocket,
keep the timing chain as tense as possible
on the exhaust side.