2005 YAMAHA YZ85 oil

3 - 35
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable endÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC
5PA307705PA307805PA30790
5PA308005PA308105PA30820
5PA308005PA30840

4 - 18
ENG
2. Contrôler:

Chemise d’eau de la culasse
Couche minérale/rouille → Enlever.

Déformation de la culasse
Hors spécifications → Surfacer.
Etapes de la mesure de la limite de déforma-
tion et du surfaçage:

Placer une règle 1 et une jauge d’épaisseur 2
sur la culasse.

Mesurer la déformation.
Limite de déformation:
0,03 mm (0,012 in)

Si la déformation est hors spécifications, surfa-
cer la culasse.

Placer un morceau de toile émeri nº 400 à 600
3 humide sur une plaque à surfacer et surfacer
la culasse 4 en décrivant des “huit”.
N.B.:
Faire tourner la culasse plusieurs fois pour éviter
d’enlever trop de matériau d’un côté.
Cylindre
1. Eliminer:

Dépôts de calamine
Utiliser un grattoir arrondi 1.
N.B.:
Ne pas utiliser d’instrument pointu. Veiller à ne pas
griffer les parties en aluminium.
2. Contrôler:

Surface intérieure du cylindre
Utiliser du papier émeri humide nº 400 à 600.
Marques de rayures → Réparer ou remplacer.
ATTENTION:
Ne pas réaléser le cylindre.
CULASSE, CYLINDRE ET PISTON
ZYLINDERKOPF, ZYLINDER UND KOLBEN
2. Kontrollieren:

Zylinderkopf-Kühlwassermantel
Mineralische Ablagerungen/Rost → entfer-
nen.

Zylinderkopfverzug
Unvorschriftsmäßig → glätten.
Arbeitsschritte: Zylinderkopfverzug mes-
sen, planschleifen

Lineal 1 und Distanzfühler 2 auf den
Zylinderkopf halten.

Verzug messen.
Verzugsgrenzwert:
0,03 mm (0,012 in)

Ist die Verzugsgrenze überschritten, den
Zylinderkopf planschleifen.

Mit Naßschleifpapier (Körnung 400–600)
3 den Zylinderkopf 4 auf einer planen
Platte in einer Achterbewegung abschlei-
fen.
HINWEIS:
Den Zylinderkopf mehrmals drehen, um
eine ebene Oberfläche zu gewährleisten.
Zylinder
1. Entfernen:

Ölkohleablagerungen
Abgerundeten Schaber 1 benutzen.
HINWEIS:
Niemals ein scharfkantiges Werkzeug benut-
zen. Insbesondere sind Kratzer im Aluminium
zu vermeiden.
2. Kontrollieren:

Zylinderinnenfläche
400er–600er Naßschleifpapier verwenden.
Riefen → instand setzen oder erneuern.
ACHTUNG:
Zylinder nicht aufbohren.

4 - 23
ENG
NOTE:
When you purchase a cylinder, you cannot
designate its size. Choose the piston that
matches the above chart.
ASSEMBLY AND INSTALLATION
Piston ring and piston
1. Install:

Piston ring 1
NOTE:

Take care not to scratch the piston or dam-
age the piston ring.

Align the piston ring gap with the pin 2.

After installing the piston ring, check the
smooth movement of it.
5PA40620
2. Install:

Gasket (cylinder) 1

Small end bearing 2

Dowel pin 3
NOTE:

Apply the engine oil on the bearing (crank-
shaft and connecting rod) and connecting
rod big end washers.

Install the gasket with the seal print side
toward the crankcase.
5PA40630
CYLINDER HEAD, CYLINDER AND PISTON

4 - 24
ENG
3. Install:

Piston 1

Piston pin 2

Piston pin clip 3
NOTE:

The arrow a on the piston dome must point
to exhaust side.

Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase
cavity.
CAUTION:
Do not allow the clip open ends to meet the
piston pin slot b.
5PA40640
5PA40650
Cylinder head and cylinder
1. Apply:

Engine oil
To piston 1, piston ring 2 and cylinder
surface.
2. Install:

Cylinder 1
CAUTION:
Make sure the piston ring is properly posi-
tioned. Install the cylinder with one hand
while compressing the piston ring with the
other hand.
NOTE:
After installing, check the smooth movement of
the piston.
5PA40660
5PA40670
3. Install:

Nut (cylinder) 1
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
5PA40680
T R..28 Nm (2.8 m · kg, 20 ft · lb)
CYLINDER HEAD, CYLINDER AND PISTON

4 - 26
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC490000
CLUTCH AND PRIMARY DRIVEN GEAR
EC498000
CLUTCH PLATE AND FRICTION PLATE
5PA40720
Extent of removal:
1 Clutch plate and friction plate removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH PLATE AND FRIC-
TION PLATE REMOVAL
Preparation for removal Drain the transmission oil. Refer to “TRANSMISSION OIL
REPLACEMENT” section in the CHAP-
TER 3.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Bolt (clutch spring) 5
3 Clutch spring 5
4 Pressure plate 1
5 Friction plate 7
6 Clutch plate 6
1

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ENG
ASSEMBLY AND INSTALLATION
Push lever shaft
1. Install:

Push lever shaft 1
NOTE:

Apply the lithium soap base grease on the oil
seal lip and push lever shaft end.

Apply the transmission oil on the push lever
shaft.5PAR0027
Clutch
1. Install:

Washer [thickness 2 mm (0.08 in)] 1

Spacer 2

Primary driven gear 3
NOTE:
Apply the transmission oil on the washer,
spacer and primary driven gear inner circum-
ference.
2. Install:

Washer [thickness 4 mm (0.16 in)] 1

Clutch boss 2
5PAR0007
5PA40850
3. Install:

Conical washer 1
NOTE:
Install the conical washer to the main axle 2
as shown in the illustration.
5PA40860
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 31
ENG
4. Install:

Nut (clutch boss) 1
NOTE:
Use the clutch holding tool 2 to hold the clutch
boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-040865PA40870
T R..70 Nm (7.0 m · kg, 50 ft · lb)
ÈÉ
5PA40880
5. Install:

Friction plate 1 1

Clutch plate 2

Friction plate 2 3
NOTE:

Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.

Use the friction plates 1 for the first and final
while paying attention to the difference in
surface pattern.

Apply the transmission oil on the friction
plates and clutch plates.
5PA40890
5PA40900
6. Install:

Push rod 2 1

Ball 2

Push rod 1 3
NOTE:
Apply the transmission oil on the push rod 1, 2
and ball.
5PA40910
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 33
ENGKICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
PRIMARY DRIVE GEAR
5PAR0008
Extent of removal:
1 Primary drive gear removal
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVE GEAR
REMOVAL
Drain the transmission oil. Refer to“TRANSMISSION OIL
REPLACEMENT” section in the CHAP-
TER 3.
Brake pedal
Radiator hose 2 Disconnect at water pump side.
1 Kickstarter crank 1
2 Right crankcase cover 1
3 Primary driven gear 1 Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR” section.
4 Nut (primary drive gear) 1 Refer to “REMOVAL POINTS”.
5Primary drive gear
1
1