ad blue YAMAHA TTR90 2001 Betriebsanleitungen (in German)

4 - 18
ENGVALVES AND VALVE SPRINGS
Valve spring
1.Measure:
lValve spring free length a
Out of specification ® Replace.
2.Measure:
lSpring tilt a
Out of specification ® Replace.
Free length (valve spring):
Intake:
28.32 mm (1.11 in)
: 26.9 mm (1.06 in)
Exhaust:
28.32 mm (1.11 in)
: 26.9 mm (1.06 in)
Spring tilt limit:
Intake:
2.5˚/1.2 mm (0.05 in)
Exhaust:
2.5˚/1.2 mm (0.05 in)
Valve seat
1.Measure:
lValve seat width a
Out of specification ® Reface the valve
seat.
Valve seat width:
Intake:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Exhaust:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Measurement steps:
lApply Mechanic’s blueing dye (Dykem) b
to the valve face.
lInstall the valve into the cylinder head.
lPress the valve through the valve guide
and onto the valve seat to make a clear
pattern.
lMeasure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
lIf the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat
must be refaced.

4 - 19
ENGVALVES AND VALVE SPRINGS
2.Lap:
lValve face
lValve seat
NOTE:
After refacing the valve seat or replacing the
valve and valve guide, the valve seat and
valve face should be lapped.
Lapping steps:
lApply a coarse lapping compound to the
valve face.
lApply molybdenum disulfide oil to the
valve stem.
lInstall the valve into the cylinder head.
lTurn the valve until the valve face and
valve seat are evenly polished, then clean
off all of the compound.
lApply a fine lapping compound to the
valve face and repeat the above steps.
lApply Mechanic’s blueing dye (Dykem) to
the valve face.
lInstall the valve into the cylinder head.
lPress the valve through the valve guide
and onto the valve seat to make a clear
pattern.
lMeasure the valve seat width again. If the
valve seat width is out of specification,
reface and relap the valve seat.
CAUTION:
Do not let the compound enter the gap
between the valve stem and the guide.
NOTE:
For best lapping results, lightly tap the valve
seat while rotating the valve back and forth
between your hands.
NOTE:
After every lapping operation be sure to
clean off all of the compound from the valve
face and valve seat.

4 - 25
ENG

CYLINDER AND PISTON
Piston pin
1. Inspect:
l
Piston pin
Blue discoloration/grooves
®

Replace, then inspect the lubrication
system.
2. Measure:
l
Piston pin outside diameter
l
Piston pin bore inside diameter
Measurement steps:
l
Measure 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)
:12.976 mm (0.5109 in)
l
Measure the piston inside diameter
b
.
If out of specification, replace the piston.
Inside diameter (piston):
13.002 ~ 13.013 mm
(0.5119 ~ 0.5123 in)
: 13.045 mm (0.5136 in)
ASSEMBLY AND INSTALLATION
Piston
1. Install:
l
Piston rings
(onto the piston)
NOTE:

l
Be sure to install the piston rings so that the
manufacturer’s marks or numbers are
located on the upper side of the rings.
l
Lubricate the piston and piston rings liberally
with engine oil.

6 - 1
–+ELEC

ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1
CDI magneto
2
CDI unit
3
Ignition coil
4
Spark plug
5
“ENGINE STOP” switch
6
Thermo switch
7
Carburetor heater
8
Rectifier/regulator
COLOR CODE
B...................... Black
Br .................... Brown
G ..................... Green
O ..................... Orange
R ..................... Red
W..................... White
EC612000
WIRING DIAGRAM
G/WB/RW/LW/RBr G
RW
WB
Y/R
O
BO
B
B
BY/RY
WY/RB
W
Y
B
GG/W
B/W
B/W
BrB/RWWWY
OO
BBW/LY/RR
W
B
B
B
W/R
Y/R
OFF
RUN
B
Y/R
B
B
Y
Y
1
23
4
5 6
7 8

B/R ................... Black/Red
B/W .................. Black/White
G/W.................. Green/White
W/L .................. White/Blue
W/R .................. White/Red
6