Mercury 6.2 exhaust gasket

[gapple12]

Just purchased a 2006 Chaparral with a 6.2 and I noticed a slight exhaust manifold gasket leak. I’m curious if I can keep the whole exhaust system with risers and all assembled and just pull the manifold away and put in a new gasket, then reassemble. I don’t want to have to replace all the gaskets.

 

[alldodge]

if I can keep the whole exhaust system with risers and all assembled and just pull the manifold away and put in a new gasket, then reassemble.

Yes, pick up some all thread all rod (3/8-16) and cut 2 pieces about 6 to 8 inches long Original bolts are 4 inch). Remove the 2 outer bolts an screw in the thread all. Now remove the 2 inner bolts and slide the manifold away. Will need to either buy a gasket where the outer holes allow the gasket to slide over the outer bolts, or cut a notch.

OEM 27-33395
Felpro 17420

 

[Scott Danforth]

I personally would want to separate the elbow from the manifold for inspection

 

[gapple12]

Thanks guys, I saw a video to use some longer headless bolts to hold the weight. I’ll probably do both sides since the other may be on its way out. Has 300 hours

if pulling the elbow apart, is there a gasket needed ?

 

[alldodge]

Yes, item 12
http://www.mercruiserparts.com/bam/subassembly/31788/13884/170

Kind of wonder what would cause it to start leaking in the first place

 

[gapple12]

Well, I’m not 100% certain that’s what it is. It’s a very slight noise in that area, can hardly hear it. might be the exhaust flapper valve further back, haven’t been able to troubleshoot much.

 

[Scott Danforth]

depending on the boat, you may need to pull the elbow to get to the flapper

 

[Lou C]

I got a couple of long bolts same thread as the exhaust manifold bolts, cut off the heads and ground a slot in the end so I could turn them out with a screwdriver after mounting the exhaust manifold. I'd try to localize the noise better first though.
I have a mechanic's stethoscope that I've used for years tracking down noises, works well. In boats noises can echo around the engine compartment and fool you sometimes.

 

[Bondo]

Well, I’m not 100% certain that’s what it is. It’s a very slight noise in that area, can hardly hear it. might be the exhaust flapper valve further back, haven’t been able to troubleshoot much.

Ayuh,..... Run yer hand along the gasketed joint areas where ya think it's leakin',....
If there's a Leak,.... You'll Feel the Heat,.....

Is this a freshwater boat, or has it been run in the brine,..??
On saltwater motors, the manifold/ riser gaskets are the Most likely to fail,.....

 

[gapple12]

Ayuh,..... Run yer hand along the gasketed joint areas where ya think it's leakin',....
If there's a Leak,.... You'll Feel the Heat,.....

Is this a freshwater boat, or has it been run in the brine,..??
On saltwater motors, the manifold/ riser gaskets are the Most likely to fail,.....

Fresh water only

 

[gapple12]

Well, Im happy to report I found the issue. The silent choice exhaust actuator brackets are rattling when not engaged. It sounds like a knock or a gasket leak and you can hear it when the engine hatch is closed. When you turn on the exhaust, it goes away. Not sure how to fix this, maybe some silicone around the pivot points. I can grab the brackets it the sounds goes away.

 

[Bondo]

Not sure how to fix this, maybe some silicone around the pivot points. I can grab the brackets it the sounds goes away.

Ayuh,..... My guess is, there used to be rubber liners on those shutters, that burnt off sometime when the exhaust was run Dry,....

 

[gapple12]

Ayuh,..... My guess is, there used to be rubber liners on those shutters, that burnt off sometime when the exhaust was run Dry,....

See this pic, I circled what is vibrating in red. I can touch them and the noise stops.

 

[alldodge]

There just worn so for the most part you will need to live it. Only other option is contact Corsa and they can rebuild them.