TM 5-4310-227-15
Section IV. TROUBLESHOOTING
Possible remedy
Probable cause
4-8. General
netting rod, or broken
piston pin (para 4-31).
This section provides information useful in
diagnosing and correcting unsatisfactory opera-
tion or failure to the air compressors or any
of their components. Each trouble symptom
Possible remedy
Probable cause
Governor defective _____ Repair governor (para 4-
stated is followed by a list of probable causes
of trouble. The possible remedy recommended
Compression poor _______ Grind or replace valves
is described opposite the probable cause.
Piston and/or piston rings Replace piston and/or pis-
4-9. Engine Hard To Start or
ton rings (para 4-31).
defective
Fails To Start
Possible remedy
Probable cause
4-13. Engine Noisy
Valves sticking or valve
Clean valve or grind valve
Possible remedy
seats (para 4-25).
Probable cause
seat inserts defective
Piston pin loose __________ Replace piston pin (para 4-
Valves warped or burned ___ Replace valves (para 4-25).
31) .
Magneto defective _____ Repair magneto (pars 4-
Piston worn or damaged ___ Replace piston (para 4-31).
19) .
Connecting rod worn ______Replace connecting rod
Fuel pump defective _____ Repair fuel pump (pars 4-
29) .
Psooible eemedy
Probable cause
Possible remedy
Probable cause
Magneto defective ________ Repair magneto (para 4-
Intake valve defective _____ Replace intake valve (para
4-25).
Valves burned, warped, or Grind or replace valves
broken
4-15. Compressor Noisy
Governor defective _____Repair governor (para 4-
Possible remedy
Probable cause
34) .
Piston pin bearing worn ___ Replace worn bearing
Compression poor _____ Replace valves (para 4-25).
Replace piston and/or
Replace worn bearing (para
Connecting rod bearing
piston rings (para 4-
worn
31).
Pressure
Probable cause
Possible remedy
Magneto defective _______ Repair magneto (para 4-
Possible eemedy
Probable cause
19) .
Replace pistons or piston
Pistons or piston rings
Engine seizure __________ Drain oil from engine base
rings (para 4-38).
Worn
and examine drained oil
Cylinder bore our-of-round _ Replace cylinder (para 4-
for presence of metal
38) .
particles. If the engine
has been operating with
insufficient oil, inspect
for possible damage
Possible remedy
Probable cause
Replace pistons or piston
such as scored piston,
Pistons or piston rings
rings (para 4-38).
worn out
scored cylinder walls,
burned or damaged con-
Cylinder. bore out-of-round _ Replace cylinder (para 4-
necting rod, bent con-
Section V. ENGINE ELECTRICAL SYSTEM
cal system. The magneto consists of the contact
4-18. General
set, capacitor, coil, magnetic rotor, and impulse
coupling The contact set, which provides a
The main function of the magneto is to sup-
ply high-voltage current for the engine electri-
timed spark for ignition, is actuated by the
