bacon1

I just purchased a 1989 223ss and the silent thunder is very faded and doesn't match the rest of the boat. I'm thinking of removing it and fabbing a custom one when the snow flies. What will I need to buy so I don't have to worry about water flowing back into the exhaust? It sounds like if I'm lucky the stock ones already have some type of back flow flappers inside? Do I need some type of caps/flappers too? I definately want to be safer than sorry, so what all do I need to buy and what sizes? Here's a pic, I'll try and get some better ones this weekend.

offthefront

iTrader: (1)

should be able to use standard 4" clamp on Flaps ...the internals may be gone .......m

http://www.youtube.com/watch?v=h8B07Q9qXBM


http://www.offshoreonly.com/forums/f...after-pix.html

bacon1

So the stock exits under the silent thunder protrude out and I just need to clamp 4" flaps on them, assuming the internals are still good? Basically I need these in 4" then?



If my internal flapper is not visible then do I need to order the entire thru-hull tube w/flappers or can you buy just replacement internal flappers?

offthefront

iTrader: (1)

I honestly cant remember what size they are ...almost sure there is a short nipple there and it should be 4" ....its a cast Aluminum unit though and pretty rough looking ....sure you dont want to just gut the box to gain some rumble?

bacon1

I did actually cut the baffles near the back exits today. I actually don't really want super loud exhaust but I don't care for the look of the swim platform, to me it just doesn't seem to flow with the back of the boat. Mine's red and really faded and cracked in a couple places. The rest of the boat is mint and it really makes the boat look dated. My buddy paints and gel coats so I could take it to him and have him paint it to match the red but I think it would look nicer with a swim platform (For the kids) and through hull. I was going to start looking to see if there are aftermarket mufflers I could use, but I've heard the 454 mag's really need a free flowing exhaust or you can have problems with heat?