Exhaust flapper valves

[tbanzer]

I have through hull exhaust and one of the flapper valves is missing inside the exhaust tips. What is the purpose of these flappers and Is it critical that they be installed?

[GofastRacer]

Stops water from going into the exhaust manifolds when the boat is sitting in the water with the motor not running!..

[Cheap Thrills]

Just as GFR said. I had a set on mine but they were the external rubber flappers that eventually rotted off. I haven't replaced them yet and haven't had any issues with water getting over the risers. Though I do try not to make any sudden stops and always come off plane easily. There could be serious damage If that cold water ever gets over the risers and onto a hot valve. not to mention Hydro Lock. I guess it's better to have them and not need them as it is to need them and not have em.
Ciao
C.T. :wink: