Thrush Aircraft S2R-R1340 Maintenance Manual page 107

Table 4-1: Engine Trouble Shooting Chart, Page 12 of 13
TROUBLE
Improper valve
clearance
Damaged intake
push rod.
Both push rods
bent on same
cylinder
Detonation
Faulty magneto
Effective: 01/01/2008
THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
PROBABLE CAUSE
Stretched valve stem
Defective bushing in rocker arm
Defective tappet roller bushing
Valve collapsed
Broken exhaust rocker arm in same
cylinder causing excessive pressures.
Broken connecting rod, allowing piston
to hang up in combustion chamber
Loose spark plugs
Spark too far advanced
Preignition
Wrong grade of fuel
Incorrect fuel-air ratio
High carburetor air temperatures
Excessive manifold pressure
Incorrect timing
Breaker points worn or burned
Points not properly tightened when
installed
Distributor finger loose on shaft
Replacement points not properly
adjusted
Magneto attaching nuts too tight
REMEDY
Replace cylinder
Replace rocker arm
Replace tappet assembly
Replace cylinder
Replace cylinder
Replace engine
Tighten spark plugs
Retime magneto
Reset magneto timing
Drain tanks, service with
correct grade
Adjust fuel-air ratio
Inspect alternate air system
Reduce throttle setting
Time magneto
Replace breaker points
Adjust breaker points
Replace magneto
Reset magneto points
Tighten nuts and retime
magneto
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