Cylinder Head
i
Cylinder Head Description
The engine is fitted with an aluminium alloy cylinder
head, which carries the camshafts, valves and spark
plugs. The cylinder head is cast as a single entity and
various components are permanently added after
machining.
The camshafts run directly in the head without
separate bearings. Valve clearances are adjusted by
changing variable thickness shims which sit between
the valve tappet bucket and the valves.
The camshafts are driven by a silent-type chain. The
cam chain is tensioned by a spring loaded device
fitted in the cylinder head, and is guided by two rubber
blades.
Oil is supplied to the head by an external feed pipe
which is situated at the right hand rear side of the
head. Once supplied to the head, the oil is distributed
along internal drillings within the head casting and
camshaft.
Single valve springs are used to close the inlet valves
and single springs to close the exhaust valves. These
valve springs have close wound coils at one end to
assist in the prevention of valve bounce at high engine
speed and to give a smooth valve actuation. When
assembling the cylinder head it is important that the
close wound, colour coded ends of the springs are
fitted downwards (towards the piston). Both the tip
and seating face of the valves are hardened to give a
long service life.
Due to the methods used to assemble the valve seat
and valve guides to the head, these parts cannot be
replaced.
A
Caution
In anv of the following operations which necessitate
the r&noval or disconnection, of the cam chain,
NEVER turn the engine without the cam chain and
tensioner correctly fitted and adjusted. In the
disassembled condition, the pistons will contact the
valves if the crankshaft is turned, causing severe
engine damage.
Cam
Cover
Removal
1.
Remove the seat (see page 16-8).
2.
Disconnect the battery, negative (black) lead first.
3.
Remove the side panel assembly (see page 16-
9).
4.
Remove the fuel tank (see page 10-88).
5.
Remove the airbox (see page 10-92).
6.
Remove the ignition coils from the cam cover.
1.
Coils
7.
Detach the secondary air injection hose from the
reed valves on top of the cam cover (see page
10-109).
1.
Spring-close hose clip
2.
Secondary air injection hose
3.
Reed valve assembly
8.
Release the throttle cables at the throttle bodies
(see page 10-96).
9.
Progressively release the cam cover bolts in the
sequence shown below.
Service Manual
-
Speed Triple
To Next Page
Loading...
Need help?
General
