Where are the flappers on my 2000 volvo 5.7 GSi DP's exhaust.?

Question

I think I might have lost a flapper valve in one of my exhaust risers. Where is this flapper located? Just after the riser's elbow? The reason I think this is that I was skiing on Saturday and everything was fine on the way down and while skiing. By fine I mean I was able to get ~5000RPM at WOT. On the way back all I got was 4100rpm at WOT. It even felt like it bogged a bit as I approached WOT. At about 70% throttle position I pulled 4100rpm easily but as I pushed past 70% rpms made no change and you could hear a slight tone difference and it might have dropped 50 or so rpm. If you think I'm off the mark with a broken exhaust flapper valve lemme know. Thanks.

Answer 1

You have to pull the engine to get to the "Y" tube. Removal of the Y-tube will allow you to replace the flapper valves.

While you have everything out you might want to consider "Captain's Call" or another type of through hull exhaust.

Answer 2

The only time the flappers come in to play is when the engine is shut off. As the boat rocks, water can enter the exhaust and enter the engine. The flappers act as a one way valve to allow exhaust out, but not back water in. Sounds more like prop, or a tune up problem (fuel or electrical) If you were feeling a bog, could be a partially plugged fuel filter not allowing enough fuel to the injectors.

Answer 3

most volvo rigs don't have them. if it does, they will be in the vertical tubes after the removeable riser and tube. they have been known to come loose and jam the exhaust at the lower unit too. this could explain a tone change.

Answer 4

The flapper is so water won't go into the exhaust.Replace it or you will damage the engine.The flapper won't effect the rpm . check the prop did you hit something???