I have a 1986 Formula 206 Spider, merc 350, prop exhaust. I want to intall thru hull exhaust preferably with a silent choice option. Most Formulas of this era had the Silent Thunder swim platform, but some had the exhuast exit straight thru and on top of the swim platform.
I am hoping to get some help from some fellow 206 owners.
Do you need to add spacers to the risers?
Are you using any elbows or is it a straight line to the transom?
There are two spots in the transom where the plywood has been precut. If I use that spot to drill thru then I have to drill thru the bolt on swim platform which is fine. But how do I seal up the tips to the transom? Its almost like I would need a flange for the swim platform and one for the transom. If someone had pictures of this that would be very helpful.
Any other pictures would be appreciated
Thanks
Chris

The only thing I hated about my 1986 206LS was the OPEN thru hull exhaust! It dumped right onto the swim platform and discolored the paint (which I had to have redone) and man can that small block bark! As I recall, there were not any special risers or spacers, just 4" rubber to the tips.

If you decide to do this, buy some tips, cut the holes, seal on both sides and run the rubber to the tips. Don't forget the flappers to prevent the water from going back to the motor. If you pull the exhaust from your risers off, you should be able to see if it is a straight shot out or not. I don't think you can modify the your existing setup for silent choice, you would need an entire system to do the modification. Some one should be able to chime in and answer that though.

Good luck! Pictures of your current set up would help too.

Dave

Thanks for the feedback.

I emailed Formula and they said that the original exhaust tip would be a merc p/n 12648A2.http://www.mercruiserparts.com/Show_...st+Kit(4+Inch)
I don't understand how this would work with my swim platform setup.
The flappers only need to be on the outlet, right? Or do I need internal flappers too?
Wouldn't the silent choice just be a y-pipe that connects to my existing exhaust and the thru hull one?

On that diagram! parts 2-5 are the internal flapper. If the pre cut holes in your transome are above the platform, they are correct. Pictures at this point will help, we could keep guessing all day.

As far as the y-pipe, I believe that this will be whichever diversion system you go with specific, but as I said before, I don't know.

Dave

Thanks again. I have some pictures of the engine compartment...I'm just having trouble trying to post them.
On my boat there is a gap between the transom and the swim platform. So the exhaust tip will exit the transom and then it will travel a few inches and then go through the swim platform.

Here are some pictures. The first is of the swim platform. Unfortunately I don't have any from underneth, but the tips would exit in the grey part of the swim platform.

The next few are of the engine compartment. You can see the recessed that are in the fiberglass. That is where the holes should be. In these pictures I have the 3" outlet risers, but I have a set of 4" outlet risers to replace them. I believe that the 4" ones are taller and they point more rearward instead of downward.

http://i1273.photobucket.com/albums/...psbe0223ea.jpg

http://i1273.photobucket.com/albums/...ps7a8a97aa.jpg

http://i1273.photobucket.com/albums/...ps88be9004.jpg

http://i1273.photobucket.com/albums/...psb7f77ce2.jpg

http://i1273.photobucket.com/albums/...ps99c17c25.jpg

You could always exit it out the side to keep the platform "clean". Was never a fan of exhaust tips exiting over the top of a swim platform.

You have the same old style power steering setup that I have on my formula. To get the exhaust over the steering gear you will need a spacer on between your manifolds and riser to maintain the correct pitch on your exhaust hose. If you raise your exhaust to clear the steering and dont use a spacer, you could have reversion issues due to not having enough pitch.

I don't think that I will have an issue with the steering gear. If you look above there is square recess where the exhaust will exit. I might need to add some spacers under the riser.
Does anyone have a picture of this setup? Or can you describe it?
Thanks