Troy-Bilt 78 Benutzerhandbuch
78/83/90 Series Horizontal Shaft Engines
100
Cylinder head installation
1.
Place a new head gasket on the cylinder, allowing
the alignment dowels to hold it in place.
See Figure 9.8.
the alignment dowels to hold it in place.
See Figure 9.8.
NOTE: MTD uses graphite head gaskets that have
a bead of silicon on them. They are not reus-
able.
able.
2.
Position the cylinder head on the engine block.
3.
Install the 4 head bolts, and tighten them to a step
torque of 38 - 41 ft-lb. (52 - 55 Nm) in an alternating
diagonal pattern. See Figure 9.9.
torque of 38 - 41 ft-lb. (52 - 55 Nm) in an alternating
diagonal pattern. See Figure 9.9.
NOTE: The bolt closest to the exhaust valve must
be the last bolt tightened. Failure to do so
will result in the head bolt loosening up.
will result in the head bolt loosening up.
NOTE: The 490 engine has an over sized bolt with
a Belleville washer in the number 4 position.
4.
Insert the push rods.
5.
Install the rocker arms.
6.
Adjust the valve lash by following the steps
described in Chapter 1: Introduction.
described in Chapter 1: Introduction.
7.
Install the throttle lever and the heat baffle.
8.
Install the muffler by following the steps described in Chapter 8: Exhaust.
9.
Install the carburetor and engine shroud, using new gaskets, by following the steps described in Chapter 3: Air
Intake
Intake
10.
Test run the equipment in a safe area before returning it to service. Check all safety features.
Figure 9.8
Graphite head
gasket
Figure 9.9
3
Exhaust
port
1
2
3
4
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