Thrush Aircraft S2R-R1340 Maintenance Manual page 101

Table 4-1: Engine Trouble Shooting Chart, Page 6 of 13
TROUBLE
Torching
(backfiring)
Engine incapable
of developing full
power
Effective: 01/01/2008
THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
PROBABLE CAUSE
Faulty ignition
Incorrect magneto timing
Vapor vent valve stuck
Inoperative cylinder
Low compression
Primer leaking
Too rich idle mixture adjustment
Improper carburetor heat control
Inoperative automatic mixture control
unit
Torching on deceleration only
Incorrectly adjusted breaker points
Malfunctioning instruments or
transmitters
Broken or damaged ignition wires
Loose spark plugs
Improper fuel
REMEDY
Check breaker points and
connection plate for
cleanliness
Time magnetos
Check that air and not fuel
is by-passed when pressure
is on
Check high-tension lead,
coil, plugs, and valve
clearance
Check valves and piston
rings for wear
Replace primer
Adjust idle mixture
Check operating
instructions
Replace automatic mixture
control
Check idle mixture and
valve clearance
Adjust points or replace
magneto
Replace malfunctioning
unit
Replace wires
Torque plugs 300 to 360
inch-pounds
Check to ensure that correct
fuel is used
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