Volvo 5.7 GI Exhaust Flapper

[Chuck McCatherin]

I own a 1997 23' Chesapeake with a 5.7Gi Volvo Penta Duo Prop DPS. It has just over 500 hours on it and the starboard side exhaust flapper is making a racket at idle. My boatyard says that Volvo no longer offers the exhaust flapper part and in fact, recommends removing them all together.<br /> <br />1) I am concerned if they remove it that salt water may make its way into the manifold and cylinders if I stop suddenly.<br />2) Are you familiar with this problem? Can you make a recommendation?<br /> <br />Thank you in advance for your help.

 

[Barnacle Boy]

Re: Volvo 5.7 GI Exhaust Flapper

Your dealer is correct. These flaps were falling apart and being sucked into the exhaust system so Volvo decided to eliminate them altogether. If you have room in your bilge, Volvo offers 3"exhaust risers.

 

[rybad]

Re: Volvo 5.7 GI Exhaust Flapper

These flappers carried over from the OMC days. My cousin just replaced them on his '97 - only because he has the inability to stray from OEM. With the high risers, you probably don't need them. I have '89 Cobras and replaced them last year, but my risers are at a shallower angle, so I wanted to make sure I don't backwash up through the exhaust. <br /><br />You have more of a choice. You have less of a chance of backwash, but if it makes you feel better - replace them. <br /><br />Just one more note. My cousin replace them this spring because when we pulled the drives to lube, I noticed the remains of one of the flappers lodged in the exhaust port of the drive! I guess this is the argument for NOT putting them in.. it can do more harm than good if it clogs up your exhaust.<br /><br />If you do replace them.. it's a pretty simply job, depending on how much room you have in your bildge to more around. I have 29' with lots of rooms, so it was easy to get the the exhuast bellows to replace them.<br /><br />-Dave

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

I believe I may have a stuck flapper on my 97 5.7 GS, can these be replaced or do I have to go to the higher risers?<br /><br />I'm not sure the 3" risers will clear in my engine area. Boat is a Glastron 205, not much room between engine cover and top of motor.<br /><br />I don't want to suck any water back into the engine.<br /><br />Thanks.

 

[Chuck McCatherin]

Re: Volvo 5.7 GI Exhaust Flapper

There was a Volvo Penta bulletin in I believe March 1999 that specifically recommends removing the flappers. I had mine removed and so far so good. The bulletin may refer to the riser height requirement but based on it being an I/O and having the riser, my guess is it will recommend taking them out. I did have an authorized Volvo trained marina do the operation. (They had access to the bulletin)

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

Thanks Chuck.<br /><br />Just to clarify, are you saying that the I/O has the risers already? I kind of think mine does cause looking at the diagrams they come way up.

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

http://volvopentaparts.stemtostern.com/VolvoDiagrams/ShowAssembly.asp?ID=71068 <br /><br />Here is a copy of the diagram I found, looks just like what I got so I assume that those are the risers on top of the exhaust manifolds.

 

[Chuck McCatherin]

Re: Volvo 5.7 GI Exhaust Flapper

Yes, that is a riser on top. Looks similar to my 5.7 GSI assembly. Once again, I did the reseach but ultimately asked my Marina to refer to the bulletin and take the final responsibility. (as if that does any good

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

Sounds good. I'm not 100% sure I want to leave them out. I'll check them out to see if they are sticking or if maybe one of them got lodged somehow. It seems that the only way water could flow back through would be if when you slow down the wake pushed it with enough pressure.

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

Chuck and everyone else,<br /><br />I pulled my risers off and pulled the tubing off and sure enough one of the flappers was broken, in fact it fell off and lodged down inside the tube towards the outlet. <br /><br />What a pain in the arse to get it out, we finally pulled it out through the exhaust outlet where it exits through the tubing to the outdrive.<br /><br />I can't believe how cheap they made these parts, it's no wonder that they don't last.<br /><br />I will update as soon as I get a chance to take it out and run it. Still not sure about running without the flappers.

 

[Bski]

Re: Volvo 5.7 GI Exhaust Flapper

So I went ahead and bought new flappers today, $40 for the pair. I talked to a couple of shops and they said that Volvo says to leave them out but they felt that it is cheap insurance to keep them in there. <br /><br />Turns out that mine were trashed cause of overheating. A couple of years back my impeller went out and the motor overheated which must of started them on their downturn.<br /><br />I'm going to put them in tonight when I get home and I'll let everyone know how things work out.