during removal so it can be easily identified and in-
stalled on the correct cylinder during assembly.
Removal/Installation
1. Securely support the motorcycle on level
ground.
2. Remove the fuel tank, air filter housing, and
surge tank and carburetor assembly as described in
Chapter Eight.
3. The small cover snaps into place on the cylinder
head. Press the arms that lock the small cover to the
large cover, and pull the small cover (
Figure 1
)
from the grommets on the bracket.
4. Unthread the cover screws (
Figure 2
) and re-
move the large cover from the cylinder head.
5. If necessary, repeat for the other cylinder head.
6. Installation is the reverse of removal.
a. Install each cover in its original location.
b. Make sure the posts on the small cover en-
gage the grommets on the cylinder head
bracket.
c. Torque the cylinder head cover screws to 4
N•m (35 in.-lb.).
CYLINDER HEAD
Removal
The procedures for removing the rear (
Figure 3
)
and front (
Figure 4
) cylinder heads are nearly iden-
tical. The few differences are noted. When remov-
ing both cylinder heads, remove the rear head first.
The Yamaha sheave holder (part No. YS-01880
or 90890-01701) or its equivalent is needed to per-
form this procedure.
1. Securely support the motorcycle on level
ground.
2. Remove the engine from the frame as described
in Chapter Five.
3. Remove the intake and exhaust valve covers
(
Figure 5
) from the cylinder head. Watch for the ca-
ble clamp on one intake valve cover bolt on the
front cylinder head.
4. Remove the two cam sprocket cover bolts (A,
Figure 6
), and remove the cam sprocket cover (B)
and its O-ring from the cylinder head.
NOTE
A breather plate is not used in the rear
cylinder head.
5. When working on the front cylinder, remove the
breather plate (A,
Figure 7
) and its O-ring from the
inside of the cam sprocket cover (B).
6. Remove both spark plugs. This makes it easier to
rotate the engine.
7. Remove the timing cover (A,
Figure 8
) and fly-
wheel nut cover (B) from the alternator cover.
CAUTION
When a cylinder is set to TDC on the
compression stroke, the timing mark
on the cam sprocket (rear cylinder) or
cam sprocket plate (front cylinder)
may not precisely align with the
pointer on the cylinder head. On some
models, the camshafts are slightly re
tarded from the factory. The mark
could be off by as much as 1/2 tooth.
Before removing a cylinder head, set
that cylinder to top dead center on the
compression stroke, and note the po
sition of the cam sprocket timing
88
CHAPTER FOUR
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