PRODUCT INFORMATION
INDEX
DATE
Dep. 2
IT-G-E-10-001e G
August 2016
ADJUSTMENT OF GAS AND ETHANOL ENGINE VALVES.
VALVE CLEARANCE
1/4
1. ADJUSTING THE VALVES
This operation aims to set the clearance between the valve lifter and the overhead-valve rocker.
With the engine cold and the cylinder being adjusted at TDC (Top Dead Center) in the compression stroke, the
clearance between the rocker arms and the valve lifters must be:
ENGINE
180/240/360/480 - HGM 240
SFGLD/SFGM/SFGRD 560
HGM420 / HGM 560
Intake
0.3 mm / 0.012 in.
0.3 mm / 0.012 in.
Exhaust
0.8 mm / 0.031 in.
0.5 mm / 0.02 in.
Adjustment procedure sequence:
1. Use the barring device to rotate the engine until cylinder #1 in the firing order is at Top Dead Center
(TDC) of the compression stroke. Watch the flywheel marks through the hole in the flywheel housing (see
page 3 for location marks on the flywheel).
NOTE:
Rotate until cylinder #1 is in the position corresponding to maximum compression, provided that
the rocker arms do NOT act on the lifters (cylinder is not in valve crossover position). Otherwise, rotate
the crankshaft one complete revolution and set the cylinder in the compression stroke.
2. At the cylinder #1 rocker arm, loosen the ball joint nut (2) and the rocker arm ball joint (3) until the rocker
arm (1) moves freely (see figure 1 on page 2).
3. Loosen the valve lifter lock nut (6) and adjusting screw on the valve lifter (7) (see figure 1 on page 2).
4. Check for proper contact between the valve lifter and the valve stems. The valve lifter should contact both
valves at the same time.
5. While applying pressure on the fixed side of the lifter, carefully rotate the adjusting screw clockwise until it
contacts the valve stem. Tighten the valve lifter lock nut (6) while keeping the adjusting screw from
turning. Be sure the valve lifter is contacting both valves evenly.
6. Inset the proper size feeler gauge between the valve lifter (5) and the rocker arm (1) (see table above).
The valve lifter should contact both valves at the same time.
7. Tighten the ball joint (3) of rocker arm (1) until it contacts the push rod socket (4) and produces a slight
drag on the feeler gauge when it is slid back and forth between the valve lifter and rocker arm.
8. Hold the push rod socket (4) with a screwdriver and tighten the ball joint nut (2).
9. Repeat the same procedure for the other set of valves.
10. Repeat the same procedure for all other cylinders by rotating the engine to bring the next cylinder to the
TDC, in the compression stroke.
5.2.4
1
O&M_2.002211.810_A_10_2016