MTZ 1220.1, Operator'S Manual

Page: 199 / 244

MTZ 1220.1/1220.3 K. Scheduled technical maintenance
K19
After every 500 service hours
Perform the operations of the previous MS
and the following ones:
О peration 22. Checking clearance be-
tween valves and rockers
Note: Check clearances on cold diesel,
having in advance checked tightness of
cylinders’ head bolts (
О peration 37).
• Remove caps of cylinders’ head covers.
• Check tightening of the bolts and nuts
fastening the rockers arm shaft brack-
ets (60 to 90 N•m).
• Turn the crankshaft until the valves
overlap in the first cylinder (the inlet
valve starts opening, and the exhaust
valve ends closing).
• Adjust the clearances in the 3, 5, 7, 10,
11 and 12 valves (counting from the
fan).
ATTENTION: Clearance between rocker
pin and end face of valve rod while check
with cold diesel engine (water and oil tem-
perature shall not exceed 60 ºC), should be
1) 0.25
05 , 0
10 , 0
+
−
for inlet valves, and
2)
05 , 0
10 , 0
45 , 0
+
−
mm for outlet valves
During adjustment of clearance between
valve-stem end and rocker arm striker in-
stall on warmed-up diesel engine:
1) intake valve - 0,25
-0,05
mm;
2) exhaust valve – 0,45
-0,05
mm;
• Crank the crankshaft to 360°, making
an overlap in the sixth cylinder, and ad-
just clearances in the 1, 2, 4, 6, 8 and 9
valves.
• To adjust the clearance, release the
locknut (1) of the adjustment screw (2)
and using a key and screwdriver set the
necessary clearance by the probe (3).
After setting the clearance, tighten the
locknut (1) and re-check the clearance
with the probe.
• After adjusting, install the removed
parts to their places.