Benelli 2009 TREK1130, Workshop Manual

Page: 367 / 582

HEAD DISTRIBUTION
ENG
5 41
VALVES SEATS CONTROL
The following procedure is applied to all valves and
valves seats.
EEliminate:
• the carbonaceous deposits
(from the contact surface and from the valve seat )
Check:
• the valve seat
In the presence of pittings/wear Replace the
head.
Measure:
• the width of the valve seat
If out of specification Replace the head.
2
1
3
3
N NOTE:
Where the valve seat and the valve face touch each
other, the Prussian blue will result removed.
Valve seat width
Inlet
0.9 ~ 1.1 mm (0.035 ~ 0.043 in)
Drain
0.9 ~ 1.1 mm (0.035 ~ 0.043 in)
Apply some blue colouring (Dykem) for mechanics
on the contact surface of the valve.
Install the valve in the head.
Push the valve inside the guide and against its seat
to leave a well-defined impression.
Measure the width of the valve seat.
A
A
A
A A
B
a
b
c
B
d