exhaust flapper failure

[swagger]

In need of advise..I have 1994 twin omc cobra 5.0 efi (302 ford) with cobra sx outdrives. I pulled off the outdrives and seen the dreaded exhaust flappers (both of them) in the bottom of the portside exhaust pipe wth one pin. I can't find the other pin(went out the exhaust?) I pulled out the old flappers and was in the proccess or replacing with new parts. I pulled off the upper exhaust pipe and boot and noticed the holes that recieve the bushing for the pins that attach to the flapper are oblong in size. I am sure if left unattended the flappers will fail again. Does anyone have any suggestions of how to fix the holes so the bushings are a tight fit? The exhaust pipe is quite expensive to replace. Oh yea the starboard also has flappers missing.

 

[Don S]

Re: exhaust flapper failure

Have a look at this service bulletin.

http://dc95.4shared.com/download/51149475/c49b77de/Volvo_Exhaust_Flapper_valves.pdf

 

[boys boating around]

Re: exhaust flapper failure

Don, Thanks for posting the service bulletin. I've been looking for it.

Swagger, I had one of my flapper valves fall off into my exhaust. Most of the actual flapper (rubber part) got discharged out through the exhaust but the pin and some larger flapper pieces stayed in the pipes.

To remove it I disassebled my whole exhaust tube from the engine down to the outdrive and pulled out the pieces that I could from there. I used a small extendable gripper tool. Then I removed the bottom of the outdrive (Sorry not an expert so I don't know the technical name) to get access to the exhaust from the back side. Removed the bellows and found the pin and the last remaining flapper pieces. Reassembled everything and it works perfect. The only thing I did not do according to the service bulletin was to fill and tape the hole. I just lowered the bellow over them. I may go back an fill them later, but have not had a problem since.

Just make sure you account for that pin or ensure that it's not stuck somewhere.

 

[swagger]

Re: exhaust flapper failure

thanks for the information don. that is a much easier fix without the worry of another failure in the future that could result extensive damage. thanks BBA for the info on how to retrieve the broken parts. i am on the hunt for that pin. what product do you suggest to fill in the holes. thank again

 

[Blackbeast]

Re: exhaust flapper failure

Don thanks for all your posts. I have a new to me 1997 Volvo 454 with a DP-S outdrive. I think I too found a piece of the flapper in the lower part of the drive during my removal and inspection. My question, I have seen this post that says no longer needed but other posts where you recommend the flapper?

Also, if the rubber has gone missing is there a need to go after the pin, it appears from the diagram to basically be a bolt through the pipe, so what is the harm in leaving it there?

 

[AZSenza]

Re: exhaust flapper failure

Some orange Hi Temp RTV would work fine to fill the holes, as far as masking tape? I'd use a complete wrap or two of aluminum tape, but I like overkill...