Volvo 4.3GL exhaust flapper valve found in outdrive exhaust....do I remove bolts

[The_Other_Dave]

I have a '99 Volvo 4.3GL with an SX-M out drive that I purchased
last fall.....used it a couple of times then winterized it and put
it away for the winter.

This spring I pulled the out drive to replace the u-joint bellows, exhaust bellows,
lube the U-joints, check the alignment and inspect the transom bearing and when
I did I found what appears to be the exhaust flapper valves stuck
down in the lower unit exhaust paths. They are burned to a crisp
but I can't find anything else they could be.

(See picture)



They must have passed completely through the y-pipe, the transom
pipe and the exhaust bellows before it got stuck in the down pipes
in the lower unit.

So I did some research here and found Don S's post of the Volvo
tech bulletin that they no longer should be used (see attached PDF)
so I am not going to replace them.

But since I am not pulling them out from the exhaust the way the tech
bulletin shows I didn't have to pull the bolts out to get them out.

So here is my question.....since the flapper valves are (what appears to be) completely
burned off the hinge bolts up in the y-pipe can I just leave the bolts in place
or should I rip the y-pipe out and seal the holes the way the tech bulletin shows?

It seems to me like I can just leave them the way they are.

Interestingly enough the system seems to be quieter than it did before but
I haven't noticed any performance or operating differences.

Any thoughts?

Thanks,

Dave

 

[Don S]

Re: Volvo 4.3GL exhaust flapper valve found in outdrive exhaust....do I remove bolts

So here is my question.....since the flapper valves are (what appears to be) completely
burned off the hinge bolts up in the y-pipe can I just leave the bolts in place
or should I rip the y-pipe out and seal the holes the way the tech bulletin shows?

You don't have to remove the Y pipe to do the fix in the bulletin, but you should remove the exhaust elbow from the exhaust manifold and check the hoses going to the Y pipe. They are probably all burned up inside and the next thing to fail. Then in the top of the Y pipe, clean the holes and patch per theb bulletin, it stops the corrosion, or at least slows it down more than nothing.

 

[The_Other_Dave]

Re: Volvo 4.3GL exhaust flapper valve found in outdrive exhaust....do I remove bolts

Don,

I am assuming that this is the sort of repair that can wait until fall......I felt the hoses connecting
the exhaust elbow to the y pipe and they don't feel brittle.

They might have been replaced.....original owner cracked the block (bad winterizing) and engine was
replaced 3 years and 25ish hours ago.

Thanks,

Dave