2003 YAMAHA TTR90 Notices Demploi (in French)

Page 193 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 23
ENG
CYLINDRE ET PISTON
ZYLINDER UND KOLBEN
Zylinderbohrung “C”47,000–47,005 mm
Konizität “T”0,05 mm
Unrundheit “R”0,05 mm
“C” = Max. D
“T” = (Max. D
1 oder D2) – (Max.

Page 194 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 24
ENGCYLINDER AND PISTON
Piston ring
1. Measure:
Ring side clearance
Use a feeler gauge. 
Out of specification → Replace the pis-
ton and rings as a set.
NOTE:
Clean carbon from the piston rin

Page 195 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 24
ENG
CYLINDRE ET PISTON
ZYLINDER UND KOLBEN
Kolbenring
1. Messen:
Ringnutspiel
Fühlerlehre verwenden. 
Unvorschriftsmäßig → Kolben (kom-
plett) mit Kolbenringen erneuern.
HINWEIS:
Vor der

Page 196 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 25
ENGCYLINDER AND PISTON
Piston pin
1. Inspect:
Piston pin
Blue discoloration/grooves → 
Replace, then inspect the lubrication
system.
2. Measure:
Piston pin outside diameter
Piston pin bore

Page 197 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 25
ENG
CYLINDRE ET PISTON
ZYLINDER UND KOLBEN
Kolbenbolzen
1. Kontrollieren:
Kolbenbolzen
Blaufärbung/Riefen → Erneuern und
Schmiersystem überprüfen.
2. Messen:
Kolbenstift-Außendurchmesse

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YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 26
ENGCYLINDER AND PISTON
2. Position:
Top ring
2nd ring
Oil 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:


Page 199 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 4 - 26
ENG
2. Positionner:
Segment de feu
Segment d’étanchéité
Segment racleur d’huile 
Décaler les becs de segment comme illus-
tré.
aBecs du segment de feu
bBecs du segment racleur d’h

Page 200 of 288

YAMAHA TTR90 2003  Notices Demploi (in French) 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