Adjusting Valve Clearance - Komatsu WA250-6 Shop Manual

SEN03836-01

Adjusting valve clearance

a Necessary tools
Symbol Part No.
1 795-799-1131
B
Commercially
2
available
a Adjust the valve clearance under the following
condition.
Engine coolant temperature: Normal tem-
q
perature
1. Remove cylinder head cover (1). For details,
see Disassembly and assembly, "Removal and
installation of cylinder head assembly".
a Removal of the engine hood is unneces-
sary.
2. Remove plate (2) and plug (3) at the bottom of
the starting motor and insert gear B1.
14
30-110
Part Name
Gear
Clearance gauge
3. Rotate the crankshaft forward (clockwise, see-
1
ing from the fan) with gear B1 and set wide slit
(b) of the rotation sensor ring to projection top
(a) of front cover.
a Projection top (a) must be within the range
of wide slit (b) when it is seen from the air
conditioner compressor side.
a If you can see the yellow marks (c) of pro-
jection top (a) and the damper periphery,
you may set them to each other.
a After the above positioning, the No. 1 cyl-
inder or No. 6 cylinder is not at the top
dead center (TDC). Take care. (The cylin-
der is at 76 – 88° before the top dead cen-
ter.)
4. Check the movement of the rocker arm of the
No . 1 c yl i nd er to j u dg e th e v al v e to b e
adjusted.
a If you can move the rocker arms of air
intake valves (IN) with the hand by the
valve clearance, adjust the valves marked
with Q in the valve arrangement drawing.
a If you can move the rocker arms of
exhaust valves (EX) with the hand by the
valve clearance, adjust the valves marked
with q in the valve arrangement drawing.
a Valve arrangement drawing
110 Testing and adjusting, Part 1

Adjusting valve clearance

WA250, 250PZ-6