AirWard Lycoming MSB 388C Valve Guide Inspection Kit

NOT APPLICABLE TO LYCOMING ENGINES WITH ANGLE VALVES Lycoming issued a Mandatory Service Bulletin, 388C, dated 11/2004, to perform an inspection of the Exhaust Valve clearance with the guide.  The purpose for the MSB was two fold: to check for not enough clearance or too much clearance between Valve Stem and Valve Guide.  Not enough clearance is caused by coking of the Valve Guide due to oil burning and attaching to the wall of the guide.  Over time this can cause a condition referred to as "Morning Sickness" - where the Exhaust Valve will tend to stick to the guide during the last engine shutdown and becomes noticeable on the next startup by a rough engine that - after running for a few seconds becomes smooth. (the valve releases from the guide).  The other condition is the valve and the guide wear to the point of causing the valve to hit the Valve Seat at an angle that could result in the valve head snapping off due to the valve hitting the seat at an angle and subjecting the valve t