Service Instruction No. 1489 C

Fuel Manifold Spring Change

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Supersedes Service Instruction No. 1489B

March 9, 2011


IO-360-L2A model engines installed in Cessna 172R and 172S aircraft; IO- 540-AB1A5 model engines installed in Cessna 182 aircraft; IO-540-AC1A5 model engines installed in Cessna 206 aircraft; TIO-540-AJ1A model engines installed in Cessna T206 aircraft with a 2 psi fuel flow divider spring (with detail P/N 2576532-1 or 2576556-1 marked on top of cover).


At owner’s discretion.

This Service Instruction identifies a new 4 psi flow divider spring Precision P/N 2577011 that is available as a replacement for the 2 psi flow divider spring for improved idle characteristics, especially in hot weather, for Lycoming engine models IO-360-L2A, IO-540-AB1A5, IO-540-AC1A5, and TIO-540-AJ1A. This Service Instruction is NOT a substitute for adjusting the fuel system and idle RPM. A check of the fuel adjustment must be done after the spring is installed.

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