Service Bulletin No. 471 B

Supersedes Service Bulletin No. 471A

February 20, 2009

MODELS AFFECTED 

Lycoming TIO-541-and TIGO-541 series engines.

TIME OF COMPLIANCE

At initial oil fill and every oil change thereafter.

The additive contains an anti-scuffing agent. Laboratory tests indicate that occasionally when an engine is first started, particularly if the engine has not been used for an extended period, during cold weather, for a very brief interval there is insufficient residual oil between moving parts; this can reduce the service life of components. The additive helps to maintain a film of lubricant to help protect the engine during the initial start-up.