100-Hour Inspection - Lycoming O-290 Operator's Manual

LYCOMING OPERATOR'S MANUAL
O-235 AND O-290 SERIES
Drain and refill sump with new oil on installation not employing replaceable external oil filter. See
latest revision of Service Instruction No. 1014 for recommended lubricating oils. Seasonal grades are
listed in Section 3, Paragraph 8 of this manual.
Remove oil suction and oil pressure screens and clean thoroughly. Note carefully for presence of
metal particles that are indicative of internal engine damage.
If engine is equipped with external oil filters, replace at this time. Before disposing of filter, check
interior for traces of metal particles that might be evidence of internal engine damage.
d. Exhaust System – Check attaching flanges at exhaust ports on cylinders for evidence of leakage. If
they are loose, they must be removed and machined flat before they are reassembled and tightened.
Examine exhaust manifolds for general condition.
e. Cooling System – Check cowling for damage and secure anchorage. Any damaged or missing part of
the cooling system must be repaired or replaced before the aircraft resumes operation.
f. Cylinders – Check rocker box covers for evidence of oil leaks. If found, replace gasket and tighten
screws to specified torque (50 in.-lbs.).
Check cylinders for evidence of excessive heat which is indicated by burned paint on the cylinder.
This condition is indicative of internal damage to the cylinder and, if found, its cause must be
determined and corrected before the aircraft resumes operation.
Heavy discoloration and appearance of seepage at the cylinder head and barrel attachment area is
usually due to emission of thread lubricant used during assembly of the barrel at the factory, or by
slight gas leakage which stops after cylinder has been in service for awhile, This condition is neither
harmful nor detrimental to the engine performance and operation. If it can be proven that the leakage
exceeds these conditions, the cylinder should be replaced.
4. 100-HOUR INSPECTION. In addition to the items listed for daily pre-flight and 50-hour inspection the
following maintenance checks should be made after every one hundred hours of operation.
a. Electrical System – Check all wiring connected to the engine or accessories. Any shielded cables that
are damaged should be replaced. Replace faulty clamps or loose wires and check terminals for
security and cleanliness.
b. Magnetos – Check condition of breaker points. Check for excessive oil in the breaker compartment, if
found, wipe dry with a clean lintless cloth. The felt located at the breaker points should be lubricated
in accordance with the magneto manufacturer's instructions. Check magneto to engine timing. Timing
procedure is described in Section 5, Paragraph 1.b. of this manual.
c. Engine Accessories – Engine mounted accessories such as pumps, temperature and pressure sensing
units should be checked for secure mounting, tight connections and terminals.
d. Cylinders – Check visually for cracked or broken fins.
e. Engine Mounts – Check engine mounting bolts and bushings for security and excessive wear. Replace
any bushings that are excessively worn.
SECTION 4
PERIODIC INSPECTIONS
4-3