Replacing exhaust manifolds on the water

[ToddC]

I have a Volvo Penta 5.7 GSI. I need to replace my exhaust manifolds and risers. The marina I am at charges about $200 just to pull the boat out of the water. I'm a bit concerned about replacing them while the boat is in the water unless I have all the precautions covered. I realize I need to plug the exhaust tubes but they are huge. The hose to the water pump is no problem. Any suggestions on how to seal the exhaust tubes off? Am I missing anything? I have changed many manifolds on cars. Somewhat mechanically inclined. I just need to make sure all incoming water is blocked. Thanks, Todd

 

[bruceb58]

Re: Replacing exhaust manifolds on the water

Lay a 2x4 across the back of your boat and measure from that to the water. Then measure down to the Y tube where the rubber hose connects from the riser and see if the level of the water is lower than that level. Hard to imagine that it wouldn't be.

 

[Don S]

Re: Replacing exhaust manifolds on the water

The top of the Y pipe may be right at or maybe below the waterline. Either leave the hose on it or plug it with an old towel while you change the manifold. Not likely you will sink in a few minutes while you plug the hole. Just be prepared and make sure your bilge pump works.

 

[Lola22]

Re: Replacing exhaust manifolds on the water

I replaced them on my 5.0GL in the water no problem. Just drained the block and went at it - did not plug anything. Much easier job than I expected. Took about 2 hours and I had never done it before

 

[bruceb58]

Re: Replacing exhaust manifolds on the water

I replaced them on my 5.0GL in the water no problem.

Depends on the boat. Depends on how the boat sits in the water. Some boats will have a problem and others won't