Doosan G430 LP Service Manual page 160

VE092-3L
3. Inspect the following areas:
(1) The cylinder head for cracks in the exhaust
ports and the combustion chambers.
(2) The cylinder head for external cracks in the
water chamber.
(3) The valves for burned heads, cracked faces or
damaged stems.
VE093-3L
4. Use the J 9666 and a flex bar torque wrench in
order to measure the valve spring pressure.
• Replace the valve spring if the spring pressure is
less than 444 N (100 lb.) at 40.9 mm (1.61 in). Refer
to Engine Mechanical Specifications.
LP Engine G430 (3.0L)
VE094-3L
5. Excessive valve stem-to-bore clearance will cause
excessive oil consumption and may cause a valve
to break.
Insufficient clearance will result in noisy and sticky
functioning of the valve and will disturb the engine
assembly smoothness.
(1) Install the valve into the guide.
(2) Install the J 8520 onto the cylinder head.
(3) Locate the indicator so that the movement of the
valve stem from side to side (crosswise to the
cylinder head) will cause a direct movement of
the indicator stem.
(4) The indicator stem must contact the side of the
valve stem just above the valve guide.
(5) Drop the valve head about 1.6 mm (0.0064 in)
off the valve seat.
(6) Use light pressure and move the valve stem
from side to side in order to obtain a clearance
reading.
(7) If the valve stem to guide clearance is
excessive, the valve must be replaced and/or
the guide must be repaired to obtain the proper
clearances. Refer to Engine Mechanical
Specifications.
- 159 - Base Engine Service Procedure