Service Instruction No. 1425 A
Suggested Maintenance Procedures to Reduce the Possibility of Valve Sticking
(Supersedes Service Instruction No. 1425)
DATE: January 19, 1988
All Textron Lycoming Reciprocating Engines.
TIME OF COMPLIANCE
Field experience has shown that engine oil contamination increases the possibility of sticking and/or stuck valves. This situation occurs when the contaminants in the engine lubrication oil become deposited on the valve stems, restricting the valve movement, and resulting in intermittent engine hesitation or miss. If corrective action is not taken to remove the deposits, a valve could become stuck causing engine damage.
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