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5.3.5. Engine cylinder head.
Valve clearance adjustment (Fig. 5.3.9a).
Check/adjust the valve clearances every 600 hours of operation and after each cylinder head
removal.
To check/adjust the valve clearances, proceed as follows:
remove the cylinder head cover,
remove the plug 1 (Fig. 5.3.9b),
set the piston of No. 1 cylinder in TDC position after compression stroke (both valves must be
closed)
– the arrow on the guard should align with “0” timing mark on the flywheel (Fig. 5.3.9b),
the correct clearances on cold engine are as follows:
-
inlet valve: 0,3 mm,
-
exhaust valve: 0,4mm,
the clearance should be measured with a feeler gauge inserting it between the top of the valve
stem and rocker lever
the sequence of valves from No. 1 cylinder is shown in the table below:
NOTE:
No. 1 cylinder is at the front of the engine.
if adjustment is needed:
-
adjust the clearance by turning the adjusting screw on the valve rocker,
-
recheck the valve clearance.
with the piston of No.1 cylinder in TDC position check and adjust the following valves:No.1
–
inlet, No.2
– exhaust, No.4 – exhaust, No.5 – inlet,
rotate the engine one complete revolution until No.1 cylinder is on TDC of exhaust stroke and
then check and adjust the valves: No.3
– inlet and No.6 – exhaust, etc.
refit the rocker cover using a new gasket and the plug in the flywheel access hole.
Fig. 5.3.9a Valve clearance adjustment.
1-Rocker arm screw. 2- Rocker arm.
3-Valve stream. 4-Filer gauge.
Fig. 5.3.9b. Timing setting.
1 - Plug. 2 - Scale.
