Thrush Aircraft S2R-R1340 Maintenance Manual page 102

Table 4-1: Engine Trouble Shooting Chart, Page 7 of 13
TROUBLE
Engine incapable
of developing full
power
(continued)
Loss of compression
4-32
THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
PROBABLE CAUSE
Valves sticking or leaking; improper
clearance
Leaks in induction system
Restriction in carburetor air scoop
Carburetor icing
Leaks in carburetor preheat system
Throttle improperly rigged
Faulty carburetor
Damaged impeller vanes
Low compression
Loose spark plug
Negative valve clearance
Warped or sticking valves
Warped valve seats
Collapsed valve
Worn or stuck piston rings
Cracked pistons or cylinders
REMEDY
Adjust clearance, free valves
or replace cylinder
Tighten an/or replace seals
and gaskets
Remove restriction
Preheat or deice, depending
upon climatic conditions.
Replace carburetor if
necessary.
Repair or replace preheat
system
Reset throttle
Replace carburetor
Replace engine
Reset valve clearance,
change cylinder
Tighten spark plug
Refer to Engine
Manufacturer's Manual
Replace cylinder
Replace cylinder
Replace cylinder
Locate trouble by
compression check. Replace
piston and cylinder
assembly
Change cylinders & pistons
for damage from detonation
Effective: 01/01/2008