Suzuki 1200 bandit, Service Manual

Page: 106 / 447

1D-38 Engine Mechanical:
Valve Seat Repair
B649G11406069
The valve seats (1) for both the intake and exhaust
valves are machined to two different angles. The seat
contact surface is cut at 45
°
.
CAUTION
!
• The valve seat contact area must be
inspected after each nut.
• Do not use lapping compound after the
final cut is made. The finished valve seat
should have a velvety smooth finish but
not a highly polished or shiny finish. This
will provide a soft surface for the final
seating of the valve which will occur
during the first few seconds of engine
operation.
NOTE
After servicing the valve seats, be sure to
check the valve clearance after the cylinder
head has been reinstalled. Refer to “Valve
Clearance Inspection and Adjustment: in
Section 0B”.
Cylinder Inspection
B649G11406058
Refer to “Engine Top Side Disassembly: ”.
Refer to “Engine Top Side Assembly: ”.
Cylinder Distortion
Check the gasket surface of the cylinder for distortion.
Use a straightedge and thickness gauge. Take clearance
readings at several places. If any reading exceeds the
service limit, replace the cylinder.
Special tool
: 09900–20803 (Thickness gauge)
Cylinder distortion
Service limit: 0.2 mm (0.008 in)
Cylinder Bore
Measure the cylinder bore diameter at six places. If any
one of the measurements exceed the limit, overhaul the
cylinder and replace the piston with an oversize piston.
The remaining cylinders must also be rebored
accordingly; otherwise, the imbalance might cause
excessive vibration.
Special tool
(A): 09900–20508 (Cylinder gauge set)
Cylinder bore
Standard: 79.000 – 79.015 mm (3.1102 – 3.1108 in)
Service limit: 79.080 mm (3.1134 in)
Piston-to-cylinder Clearance
Refer to “Piston and Piston Ring Inspection: ”.
Intake Exhaust
Seat angle 15
°
/45
°
15
°
/45
°
Seat width
0.9 – 1.1 mm
(0.035 – 0.043 in)
0.9 – 1.1 mm
(0.035 – 0.043 in)
Valve
diameter
30 mm
(1.18 in)
27 mm
(1.06 in)
Valve guide
I.D.
5.000 – 5.012 mm
(0.1969 – 0.1973 in)
5.000 – 5.012 mm
(0.1969 – 0.1973 in)
1
I649G1140361-01
I649G1140258-01
(A)
I649G1140259-02
I649G1140260-01