Various 2 cycle engine manufacturers, including Polini, recommend that the reed valve be replaced every 100 hours. It is rare that the entire valve is damaged in some way. It is just the reed petals that are worn out or damaged. Pilots can save some expense by replacing just the reed petals. These custom manufactured reed petals are an exact replacement fit of the stock petals that are in the Top 80. The petals supplied by Miniplane (shown above: M16/1) on the other hand, must be modified to fit the reed valve mounts. When replacing the petals be sure to use blue Threadlock on the screws and make certain the new petals are as flat as possible.