Table 5-1. Direct Support and General Support Maintenance Troubleshooting-continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4. ENGINE HARD TO START OR FAILS TO START
Step 1. Inspect for defective valves or valve seat.
Replace defective valves or valve seat.
Step 2. Inspect for worn, stuck, or broken piston rings.
Replace defective piston rings.
Step 3. Inspect for defective timing gear or camshaft.
Replace defective timing gear or camshaft.
5. OIL CONSUMPTION EXCESSIVE
Step 1. Inspect for worn, stuck, or broken piston rings.
Replace defective piston rings.
Step 2. Inspect for worn or scored cylinder wall.
Replace worn or scored engine block.
Step 3. Inspect for defective seal.
Replace defective seal.
6. ENGINE KNOCKS
Step 1. Inspect for defective connecting rod bearing.
Replace defective connecting rod bearing assembly.
Step 2. Inspect for defective piston pin.
Replace defective piston assembly.
Step 3. Inspect for defective piston.
Replace defective piston.
Step 4. Inspect for defective main bearing.
Replace defective main bearing.
Step 5. Inspect for stuck valve.
Grind or replace defective valve.
7. ENGINE SMOKES EXCESSIVELY.
Step 1. Inspect for stuck, worn, or broken piston rings.
Replace defective piston rings.
Step 2.
Piston worn or broken.
Replace defective piston.
Step 3. Inspect for worn or scored cylinder walls.
Replace defective engine block.
Section III. GENERAL MAINTENANCE
5-6. General
This section contains direct support maintenance
data that will be needed by direct support main-
tenance personnel and may be referenced for repair
of the tank and pump unit.
5-7. Tabulated Data
a. Nut and Bolt Torque Data. For nut and bolt
torque data, refer to table 5-2.
b. Engine Overhaul Data.
Bore . . . . . . . . . . . . . . . . . . . . . 2 7/8 in.
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ¾ in.
Displacement . . . . . . . . . . . . . . . . . 17.8 cu. in.
Rotation . . . . . . . . . . . . . . . . . . .Clockwise
(flywheel end)
Brake horsepower . . . . . . . . . 4.49 at 3000 rpm
Spark plug gap . . . . . . . . . . . . . . . . . . . . 0.030 in.
Magneto points . . . . . . . . . . . . . . . . . . 0.015 in.
Carburetor . . . . . . . . . . . . . . . . . . . . . . . . Idle at 1,000-
1,200 rpm
c. Repair and Replacement Standards. Table 5-3
lists
the
manufacturer’s
sizes,
tolerances,
desired
c l e a r a n c e s , a n d m a x i m u m a l l o w a b l e w e a r a nd
clearances.
Table 5-2. Nut and Bolt Torque Data
Cylinder head screw . . . . . . . . . . . . . . . . . . . . . . 14-18 ft-lb
Oil pan screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8 ft-lb
Connecting rod cap bolt . . . . . . . . . . . . . . . . . . . 14-18 ft-lb
Main bearing cap bolt . . . . . . . . . . . . . . . . . . . . 14-18 ft-lb
5-2
