1995 OMC 5.8l Y-Pipe flapper valve damage

[ryanam]

Hi,

I have a 1995 OMC 5.8l EFI that has some damage where the flapper valve pin sits. There has been a groove worn down the sides and is causing a ticking noise at idle. I know the proper way to repair it would be to replace the y-pipe, but I dont want to pull the engine unless I have too.

I was wonder if there are any fixes to this problem. One idea that i am pondering is locating the mounting holes offset from the original ones and filling the original holes with JB weld.

Any input would be appreciated.

Thank

 

[jerryjerry05]

Re: 1995 OMC 5.8l Y-Pipe flapper valve damage

They removed the flapper on later drives.Maybe run it without it.
Any JB repairs probably won't hold.
The tube will heat up and cool down.
Normal expansion/contraction will make it fall out.
The best way is find someone to weld it.

 

[ryanam]

Re: 1995 OMC 5.8l Y-Pipe flapper valve damage

Ok, thanks. How likey am I to have water backflow into the engine without that valve in place?

 

[Dtruedog]

Re: 1995 OMC 5.8l Y-Pipe flapper valve damage

ryanam,

Here's a suggestion for a fairly easy fix:

JB Weld would work if you use it to hold a small bushing sleeve in place into which the flapper shaft is inserted. I would try to locate a piece of SS tubing that allows a slip fit over the end of the shaft. A parts diagram indicates the hole for the shaft goes all the way through the wall of the pipe. Bore it if not already large enough diameter(drill or small round file perhaps) to accommodate the diameter of the short tubing piece. Slide the SS bushing over the pin and lock the bushing in place with the JB Weld, filling the gouged inner part of the pipe, inside edge flush with the exhaust pipe inner surface, being careful to maintain alignment of the shaft/pin in the exhaust pipe wall so there is no lateral movement that would cause the flapper to hang up in an open position. Any outside overhang can be ground off flush.

Otherwise, I would probably just remove the flapper!

Good luck!

 

[Jammer864]

Re: 1995 OMC 5.8l Y-Pipe flapper valve damage

If you can find a 90 degree drill adapter, just drill two new holes for the pin slightly higher than the existing holes and RTV the old holes shut. By going a little higher rather than lower, you will keep the holes within the area covered by the rubber connector on the outside of the Y pipe to Elbow joint. I had one of my flappers dislodge and block the exhaust into the outdrive. After removing it, I repaired the damage to the pipe holes (that is similar to your damage) with JB Weld and it worked just fine. I then became aware of the Service Bulletin from Volvo that referred to removing the flappers altogether and filling the holes with RTV. The next time I had the elbows off I did that mod and got rid of the flappers. That was 5 years ago and it was in a 94 Four Winns Horizon with a 5.8FI. No evidence of water ingestion since removing the flappers.