3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as
weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals. If
you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
race
Every third
(or
500 km)Every fifth
(or
1,000 km)As
requiredRemarks
ENGINE OIL
Replace
Inspect
VALVES
Check the valve clearances The engine must be cold.
Check the valve seats and
valve stems for wear. Inspect
Replace
VALVE SPRINGS
InspectCheck the free length and
the tilt.
Replace
VALVE LIFTERS
InspectCheck for scratches and
wear.
Replace
CAMSHAFTSInspect the camshaft
surface.
Inspect the decompression
system. Inspect
Replace
TIMING CHAIN SPROCKETS, TIMING
CHAIN
InspectCheck for wear on the teeth
and for damage.
Replace
PISTON
InspectInspect crack
Inspect carbon deposits and
eliminate them. Clean
Replace
PISTON RING
InspectCheck ring end gap
Replace
PISTON PIN
Inspect
Replace
CYLINDER HEADInspect carbon deposits and
eliminate them.
Change gasket Inspect and clean
CYLINDER
Inspect and clean Inspect score marks
Inspect wear
Replace
CLUTCH
Inspect and adjust Inspect housing, friction
plate, clutch plate and spring
Replace
TRANSMISSION
Inspect
Replace bearing
SHIFT FORK, SHIFT CAM, GUIDE BAR
InspectInspect wear
4 - 77
ENGCYLINDER HEAD
INSPECTION
Cylinder head
1. Eliminate:
Carbon deposits
(from the combustion cham-
bers)
Use a rounded scraper.
NOTE:Do not use a sharp instrument to
avoid damaging or scratching:
Spark plug threads
Valve seats
2. Inspect:
Cylinder head
Scratches/damage
→
Replace.
3. Measure:
Cylinder head warpage
Out of specification
→ Resur-
face.
Cylinder head warpage:
Less than 0.05 mm
(0.002 in)
Warpage measurement and
resurfacing steps:
Place a straightedge and a
feeler gauge across the cylinder
head.
Use a feeler gauge to measure
the warpage.
If the warpage is out of specifi-
cation, resurface the cylinder
head.
Place a 400 ~ 600 grit wet
sandpaper on the surface plate,
and resurface the head using a
figure-eight sanding pattern.
NOTE:To ensure an even surface rotate
the cylinder head several times.
ASSEMBLY AND INSTALLATION
Cylinder head
1. Install:
Dowel pin
1
Cylinder head gasket
2
Timing chain guide
(exhaust side)
3
Cylinder head
4
NOTE:While pulling up the timing chain,
install the timing chain guide
(exhaust side) and cylinder head.
New
CONTROLE
Culasse
1. Eliminer:
Dépôt de calamine
(de la chambre de combustion)
Utiliser un grattoir arrondi.
N.B.:
Ne pas utiliser d’instrument pointu pour
éviter d’endommager ou de rayer:
Filets de bougies
Sièges de soupape
2. Contrôler:
Culasse
Rayures/endommagement →
Remplacer.
3. Mesurer:
Déformation de la culasse
Hors spécifications → Surfacer.
Limite de déformation de la
culasse:
Moins de 0,05 mm
(0,002 in)
Etapes de la mesure de la limite de
déformation et du surfaçage:
Placer une règle et une jauge
d’épaisseur sur la culasse.
Utiliser une jauge d’épaisseur pour
mesurer la déformation.
Si la déformation est hors spécifi-
cations, surfacer la culasse.
Mettre un morceau de toile émeri
n° 400 à 600 humide sur une pla-
que à surfacer et surfacer la culasse
en décrivant des “huit”.
N.B.:
Tourner la culasse plusieurs fois pour
obtenir une surface lisse.
ASSEMBLAGE ET MONTAGE
Culasse
1. Monter:
Goujon 1
Joint 2
Guide de chaîne de distribution
(côté échappement) 3
Culasse 4
N.B.:
Monter le guide de la chaîne de distribu-
tion (côté échappement) et la culasse
tout en soulevant la chaîne de distribu-
tion.
New
CULASSE
