Thermo King UT-1200, Manual

Page: 110 / 169

Engine Maintenance
110
c. If the rocker arms are loose, the engine is
at top dead center of the compression
stroke for the number 1 cylinder.
d. If the rocker arms are tight, the engine is at
top dead center of the exhaust stroke for
the number 1 cylinder. Rotate the engine
360 degrees to place the engine at top dead
center of the compression stroke for the
number 1 cylinder.
3. Use a feeler gauge to check the valve
clearance on both valves for the number 1
cylinder. The valve clearance for both the
intake valves and the exhaust valves should be
0.006 to 0.010 in. (0.15 to 0.25 mm).
NOTE: Check to make sure that the valve
stem cap is in good condition and is
positioned squarely on the top of the valve
stem. Replace the valve stem cap if it shows
significant wear.
4. Adjust the valves if necessary by loosening
the lock nut and turning the adjustment screw
until the valve clearance is correct.
5. Hold the adjustment screw in place and
tighten the lock nut.
Figure 185: Adjusting Valves
6. Recheck the valve clearance.
7. Place the engine at top dead center of the
compression stroke for the number 3 cylinder.
a. Rotate the engine in the normal direction
of rotation (counterclockwise viewed from
the flywheel end) until the top dead center
timing mark for the number 3 cylinder on
the flywheel lines up with the index timing
mark on the starter mounting plate.
b. Check the rocker arms on the number 3
cylinder to see if they are loose.
c. If the rocker arms are loose, the engine is
at top dead center of the compression
stroke for the number 3 cylinder.
d. If the rocker arms are tight, the engine is at
top dead center of the exhaust stroke for
the number 3 cylinder. Rotate the engine
360 degrees to place the engine at top dead
center of the compression stroke for the
number 3 cylinder.
8. Check and adjust both valves for the number 3
cylinder.
9. Place the engine at top dead center of the
compression stroke for the number 2 cylinder.
a. Rotate the engine in the normal direction
of rotation (counterclockwise viewed from
the flywheel end) until the top dead center
timing mark for the number 2 cylinder on
the flywheel lines up with the index timing
mark on the starter mounting plate.
b. Check the rocker arms on the number 2
cylinder to see if they are loose.
c. If the rocker arms are loose, the engine is
at top dead center of the compression
stroke for the number 2 cylinder.
d. If the rocker arms are tight, the engine is at
top dead center of the exhaust stroke for
the number 2 cylinder. Rotate the engine
360 degrees to place the engine at top dead
center of the compression stroke for the
number 2 cylinder.
10. Check and adjust both valves for the number 2
cylinder.
11. Replace the cylinder head cover.
1. Adjustment Screw
2. Lock Nut
Figure 184: Valve Clearance
1
2
AGA148
AGA114