Silent Thunder exhaust flaps
 

One of my exhaust manifolds went bad last weekend and upon removing the Gil tailpipes, I see that there are no flaps on the tips that go through the transom into the swim platform. Is this normal? There is a bar that runs vertically about the size of a pencil in the middle of the tips. Does anyone know where I can get some Merc/ Gil manifolds?

Thanks, Craig

Never having my Silent Thunder platform off, I don't think there's any internal flappers. Only the ones at the end of the platform.
Can't see why you'd need them on inside, the baffles should stop any water from backwashing.

Craig,
My 223LS does have flappers in the tailpipes. They were both half gone, so I replaced them with the Merc parts, which was a mistake. Something like $100 for two. I saw them in the Cp Performance catalog for about $40. Looked identical. If you do replace them make sure you put some sort of silcon on the top and bottom, or they will rattle. The keepers are rivited to the inside of the tailpipes. Mine looked okay, so I didn't replace them.

Scott

thanks guys,
Check this out. The cheapest that I could find replacement Gil/Mercruiser manifolds was $1375 per side. I called Gil Marine directly and they charge $1175 per PAIR. Same manifold but it doesn't say Mercruiser on the side. WTF!! Can you guess which ones I ordered:D :D :D

Craig, I had a baffle come loose on my 272 last week. when I pulled it out. I saw exactly what you did. thru hulls with a narrow piece vertically down the center. no flaps. I assume this is ok as my previous boat (211 liberator) had thru hulls with no flappers or no baffles at all???

the baffles in my silent thunder are about 10" away from the transom. only one baffle (vertical wall with 1" gap at bottom) each chamber.

when they are removed. only the swim platform keeps waves from entering the exhaust. but i think just the slope of the exhaust pipe is what trully keeps the water out because I think many have open exhaust.(other boat makes)

Not to get to far off the subject but do any of you have a exhaust leak between the transome and the silent thunder? If so what did you do to fix.

Russ

Russ see your Private message

My Silent Thunder platform also leaks. I think it needs a new gasket. That's going to have to wait until winter:D :D
Did you guys cut out the baffle from the inside or drill holes?
How much louder is it? My boat is pretty loud on plane but is way too quiet at idle.

I'm still waiting for my new Gil manifolds. They are supposed to be here today. It's hard to believe that they don't make a bunch of them in the winter to establish some excess stock:mad:


Thanks, Craig

I only have one port that does not have the baffle now. it is louder, but only one engine bank. I was going to drill two 2" holes each, but seing how simple the baffle is I will cut them out when I remove the platform.

heck. maybe I will drill them out this week, then do the rest when I remove the platform... yea... gotta go get a long drill :D

Rambunctious,
clean out your e-mail box

Russ