Perkins 103-06 Workshop Manual page 20

c. Lapping of contact face of the valve seat
Correct valve seat contact using a valve
lapper and lapping compound.
When using a new cylinder head, obtain
correct seat contact width and seat recess
using the seat cutter. Then, carry out lapping.
w.
D. Valve spring
Visually inspect the valve spring for damage.
Position the valve spring on a flat surface and
check the squareness of it using a square, as
shown in the illustration. If it exceeds allowable limit,
replace the spring.
Using a spring tester, check spring force and
free length.
Replace if found to be beyond allowable limit. 103-
09/10/Perama M25/M30
Standard
value
Squareness (mm) (1.2).047"
Free length (mm) (35)1.378"
Spring force (kg) (8.1) 17.91bf
(when compressed
to 30.4mm 1.197")
103-06
value
Squareness (mm)
Free length (mm)
Spring force (kg)
(when compressed
to 28.3mm)
f
PB036
Allowable
limit
(2.0).079"
(33.5)1.319"
(7)15.4 lbf
Standard Allowable
limit
(1.0).039" (1.2).047"
(33)1.299" (31.5)1.240"
(6.9)15.21bf (6.0)13.21bf
Squareness
E. Inner face of combustion chamber
Pull out the cap and insert from the cylinder
head. Check and clean the combustion chamber.
Cap (not fitted on 103-06)
- Reassembly
Reassemble the parts in the reverse order of
disassembly.
NOTE: When assembling
retainer and collets, take care not to damage
the valve guide seal.
Cylinder block
- Inspection and Correction A.
Cylinder block top face
Inspect the cylinder block top face for cracks,
damage and warping in the same way as for
the cylinder head.
If outside limit, replace cylinder block.
Standard value
Less than 0.05mm (
.002")
4~
'
I
OP
W
P B 1 2 8
Insert
the valve spring,
Allowable limit
0.12mm (
005')