Yanmar 1GM User Manual page 114

108
CHAPTE R SIX
cleaning. look for cracks or oth er visible signs ofdamage.
Clean the passages with a stiff spiral brush. then blow
them out with comp ressed air.
Feeler
gauge
NOTE
Ifdepasits aref ound in the inta ke or exhaus t
ports, remove the valves and dean the ports.
0
0
o
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4. Place the new head gasket over the cylinder head studs
on the block. Be sure the TOP mark (Figure 13) on the
gasket is up.
5. Carefu lly lower the head onto the cylinder block.
6. Apply engine oil to the threads on the cylinder head
studs.
7. Install and tighten the cylinder head retaining nuts fin-
ger-tight.
8. Tighten the nuts and bolts following the sequence
shown in Ftgurc 14 to the torque specified in Table 4.
Tighten the nuts and bolts in three equal steps until reach-
ing the final torque setting.
9. If removed, install the sacrificial anode into the cylin-
der head.
10. Attach the oil line fitting
10
the cylinder head.
I I. Install the push rods in their orig inal position.
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Installation
I. Make sure the cylinder head and block gasket surface s
are clean.
2. Recheck all visible oil and water passages for cleanli-
ness.
3. Apply Three Bond 50 gasket scaler to both sides of a
new cylinder head gasket.
6. Clean away all carbon on the piston top.
7. Chec k the cy linder head studs for dama ge and repl ace
the m
if necessary, Ir a
stud is loose, tighten
it
us ing the fo l-
lowing procedu re:
a. Install I\\'O nuts on the stud as shov... n in Figure 11.
typical.
b. Rotate the nuts so they contact eac h other. then hold
onc nut and lighten the other nut against the first
nut.
c. Tighten the stud in the cy linder block by turn ing the
top nut until reaching a torque of 60 Nom (44
ft.-lb.).
d. Hold the bottom nul, loosen the top nut, and remove
both nuts.
8. Check the threaded rocker ann support stud for dam-
aged threads. Replace if necessary.
9. Check for warpage of the cylinder head-to-block gas-
ket surface with a straightedge and feeler gauge ( Ftgure
12). Measure diagonally, as well as end to end. If the gap
exceeds 0.07 mm (0.003 in.). have the head resurfaced by
a machine shop.