Exhaust flappers for Silent Thunder
 

Anyone know where I can get the exhaust flappers (butterfly style) that go at inlet of the Silent Thunder system for a 1989 272SR1?

Try cpperformance.com I think they should what your looking for. Hope this helps. mark

What's the point:confused: Mine have been missing for years with no known problems. I was going to replace them myself , but figures I would only burn up the new ones:(
The outside ones are still intact and seem to do the job:)

I just took off my silent thunder to replace the seal, low and behold I only had two half pieces left. The box itself should stop any water from getting up there. At least in the amount it would take to hit the tubes. So I believe I will not replace them. Outside flaps are good and the baffles are stock (no holes).

Silent Thunder
 

Hey Russ,
I'm getting ready to remove my silent thunder swim platform this weekend to replace the seals. How hard was it to get the box off? Can two people do it or do you need three?

Craig

I need to follow this operation.
Mine needs new seals too. Where did you get them? Formula, or is it something I can get elsewhere?

Iggy,
I called Robert Nelems (magicfloat) and he had them shipped directly to me from Formula. $20 for the parts. There is two o-rings that go around the thru hull tips and a "refrigerator-door type seal that goes around the perimeter of the box. Like I said, I'm going to do it this weekend, I'll post the results on how hard it is. I've been told to check the wooden backplane that goes against the transom real good for rot.

Craig

Russ,

My boat has twin big blocks with superchargers and sits quite low in the stern and when I’m out we often have people sitting on the platform or sundeck.

I have found that Stainless Marine have some flappers that can be retrofitted in the hose so I think I will go with some of those.

Thanks for the help.

I would like to hear more about replacing the seals on the Silent Thunder as i have my motors out now so it would be a convenient time to take it off.

Ian T.

Ok guy's, I started this deal just for the gaskets but it turned into a lot more. Craig hit the money right on the spot. Look for rot!!!!!!! I will start the pic's of this project.

Yea!!!

Pics would be great. How many people to remove the box?

The back of the silent thunder

Rott number 2

This was untouched and how I found it when it came off the boat. I am not sure if it is original. The rott is only the top half of the box. I believe that there is only plywood here for the upper mounting tow hooks,as to not crush the glass when mounted.

The other problem my silent thunder box had was at the tow hooks. Stress cracks developed I would imagin due to no support from the back. I have seen many Formulas with this problem. If you see this on yours I would bet you have rott.

Pic 2

pic 3

The removal of the platform was easy I did it myself with the help of a fork truck to support the weight. If you do not have a fork at your disposal I would recomend that you have a second person, three would be nice. All you need to do is remove all four tow hooks and the two L brackets under the middle. Do it in this order The small L brackets first, the lowwer tow hooks second, then remove the nuts from the upper tow hooks, get out of the boat and pull it off.

Starting to get naked back there. Bell housings and gimbals are coming off next. I need some input on what kind of medea to use for blasting the gimbals, Is sand to harsh?

Russ, I've read horror stories about the rot. I hope mine isn't like that. I do know that sometimes mine will leak exhaust around the outer edge seal if I'm standing on it. I pray it's just the tail pipe seals gone bad.
In your pic #2 it looks like there was exhaust leaking around the tow hook. Is that right?

Iggy,
Yes you are right. There was ehaust leaking there. Don't get me wrong it looks uggly but it is not that hard of a repair. Just because the silent thunder is rotting means nothing about the hull. The rest of my boat is mint, it's just the drives and silent thunder need to be looked after.

Rott cut out

Pic 2

The inside of the box was totaly unaffected

From the start

My little baby

Cay,
BBC the way to go:D Post a pic of yours with the superchargers

I know it's seperate from the hull.
I know it can be repaired. I just hate the thought of what I might find.
I'll order the seals and pull it off sometime this summer. If I find any trouble I guess I could buy some tips and run open pipes till it's repaired. The wife'll love that. :rolleyes:

Has your boat ever been stored in the water?
Or has it been always trailered?

I wonder if that makes a difference.

I know the hot steam is a contributor to the rot but I wonder if always being in the water and not having the water boxes drained and allowed to dry out are a factor. Mine's always on the trailer and the boxes drained after use.

Iggy,

The boat has had a half and half life, in the water and on the trailer, I am the 3rd owner. Fresh water, short season, northern boat.

I thought about tip's and a tube swim platform but I love the silent thunder look and it's nice to be quiet when slow going.

Re: Exhaust flappers for Silent Thunder
 

another TTT