Remove exhaust flapper valves or leave them alone?

[perna00]

I've got the 5.0 omc (ford) engine. I removed the exhaust manifolds for some work I had to do for the boat and see the flapper valves are still installed. They move decently freely and was wondering if I should remove them. I read that there is a service bulletin that says to remove them since they can become unattached and clog the exhaust openings. Should I leave mine alone, somehow service them to prolong life, or remove them? If I remove them, is there any other precaution I should take?

 

[sam60]

Re: Remove exhaust flapper valves or leave them alone?

I've got the 5.0 omc (ford) engine. I removed the exhaust manifolds for some work I had to do for the boat and see the flapper valves are still installed. They move decently freely and was wondering if I should remove them. I read that there is a service bulletin that says to remove them since they can become unattached and clog the exhaust openings. Should I leave mine alone, somehow service them to prolong life, or remove them? If I remove them, is there any other precaution I should take?

If the shaft seals and flappers are fine, leave them in. If in dought get new parts. Water coming in though the exhaust was evident in the starboard side of my heads and block when I tore it down. Starboard side flapper was melted down.

 

[perna00]

Re: Remove exhaust flapper valves or leave them alone?

ok, I'll leave them in since they are not disfigured or damaged. Is there anything I can do/spray on them to help them out in the long run? Maybe a lubricant on the shaft?

 

[Jammer864]

Re: Remove exhaust flapper valves or leave them alone?

I had one of my flappers fall into the bottom of the exhaust and block it, causing an inability to make enough power to plane out. Revved up just fine in neutral, but not in gear. I put in new parts two years ago and during de-winterization this year, took a look at them and the rubber bushings that locate them in the exhaust pipe were failing again and the whole assembly was loose. I ended up removing both flappers and sealing the holes with rtv. Id say leave them in unless you like replacing them every couple years.