Kohler COMMAND CH18, Service Manual

Page: 225 / 232

11.27
Section 11
Reassembly
11
Install Valve Covers
Three valve cover designs have been used. The
earliest type used a gasket and RTV sealant between
the cover and sealing surface of the cylinder head. The
second type had a black O-Ring installed in a groove
on the underside of the cover and may have metal
spacers in the bolt holes. The newest design uses a
yellow or brown O-Ring, with bolt hole spacers
molded in place. The tightening torque differs
between gasket and O-Ring style covers. Kits are
available for converting to the latest O-Ring type
covers. Differences are pointed out in the following
installation steps.
NOTE: Do not scrape old RTV sealant (if used) off
the sealing surface of the cylinder head as
this could cause damage and result in leaks.
The use of gasket remover solvent (paint
remover) is recommended.
1. If using the gasket or sealant type cover, prepare
the sealing surfaces of the cylinder head and
cover as directed in Service Bulletin 252. Refer to
Section 2, for approved sealants. Always use fresh
sealant – using outdated sealant could result in
leakage. With O-Ring type covers, make sure the
sealing surfaces are clean.
2. Make sure there are no nicks or burrs on the
sealing surfaces.
3. For covers requiring RTV sealant, apply a 1.5 mm
(1/16 in.) bead to the sealing surface of both
cylinder heads, install a new valve cover gasket
on each, then apply a second bead of sealant on
the top surface of the gaskets. For O-Ring type
covers, install a new O-Ring in the groove of the
covers.
Do not use gaskets or RTV sealant.
4. Locate the cover with the oil fill neck on the same
side as removed and install the lifting strap in the
original position. With O-Ring type covers,
position the cover on the cylinder head. If loose
spacers were used, insert a spacer in each of the
screw holes. On both types, install the four hex
flange screws in each cover and finger tighten.
5. Torque the valve cover fasteners to the proper
specification using the sequence shown in Figure
11-89.
Figure 11-90. Tightening Valve Cover Screws.
Install Air Cleaner Assembly
Refer to Section 4 for air cleaner reassembly
procedure.
Standard Air Cleaner
1. Attach the rubber breather hose to the breather
cover. Connect the fuel inlet line to the carburetor
and secure with a clamp. See Figure 11-91.
Figure 11-89. Valve Cover Fastener Torque
Sequence.
NOTE: Fastener #2 may secure fuel pump bracket on
earlier models.
1
2
3
4
Gasket/RTV style cover .............. 3.4 N·m (30 in. lb.)
Black O-Ring style cover
with shoulder screws .......... 5.6 N·m (50 in. lb.)
with screws and spacers .... 9.9 N·m (88 in. lb.)
Yellow or Brown O-Ring style cover
with integral spacers ........... 6.2 N·m (55 in. lb.)