Kohler KD477-2, Руководство по ремонту

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KD 477-2 Workshop Manual_cod. ED0053029370_
1° ed
_ rev.
00
IX
5
6
7
8
Cylinder heads
Details of fig. 5:
1 . Cylinder head - 2 . Pipe - 3 . O-Ring - 4 . Rockerarms - 5 . Rockers -
6
. Cotters -
7
. Plates -
8
. Springs -
9
. Guides -
10
. Seats -
11
. Valves
- 12 . Tappets - 13 . Camshaft.
The heads are of aluminium with inserted guides and valve seats in
cast iron. Make sure there are no cracks or imperfections. Should it
be so, replace according to the instructions given in the spare parts
catalogue.
Never remove head while still hot in order to avoid defor-
mation.
Fitting of new guides always requires grinding of the valve seats (see
page 19).
Valve guides with an external diameter increased by 0.10 mm are
available.
If the inlet clearance between valve and guide is lower than 0.08 mm
and the outlet clearance is lower than, 0.10 mm , the wear on B is
less than 0.03 mm and A is more than 0.05 mm , recondition the val-
ve by grinding face
P
to
45°
(fig. 7).
As a result of prolonged engine operation, the hammering of the val-
ves on their seats at high temperature causes the face of the seats to
harden and hand grinding is made difficult. It is thus necessary to re-
move the hardened surface with a
45°
cutter mounted on a valve seat
grinding tool (fig. 8). Final fitting can then be carried out manually with
the cutters listed below.
Cut dimensions for valve seats
CHECKS AND OVERHAUL
Valves - Guides - Seats
Clean the valves with a wire brush and renew them if the valve heads
are deformed, cracked or worn.
Check clearance between valve and guide with a micrometer on
stem B (fig. 7) and with a go/no go gauge as shown in fig. 6 (tool cod.
00365R0450
).
Change the guide if the maximum gauge diameter passes through it,
as it has passed the maximum permissible wear.
After having fitted the new guide, check exact diameter using the “go”
end of the gauge and if necessary grind it to the dimensions indicated
in the table using the adjustable grinder (tool cod. 00365R0850 ).
Engine Guide
Ø Guide
mm
Ø Gauge mm
go no go
Inlet
Outlet
Engine
Inlet
Ø guide
Outlet
Ø guide
7,000 ÷ 7,010 7,079 7,000
KD 477-2
KD 477-2 40 x 12 mm
A x B A x B
7 mm 38 x 12 mm 7 mm