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Fmf 4.1

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Hey guys...I have a KTM SX450F. I was just wondering if there was any way I could make it quieter without getting a silencer...

It has a FMF 4.1 without the megabomb.

Can I buy an insert or something?

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Hey guys...I have a KTM SX450F. I was just wondering if there was any way I could make it quieter without getting a silencer...

It has a FMF 4.1 without the megabomb.

Can I buy an insert or something?

You can get an insert for sure. DB DAWG is a good one. Be sure to get the spark arrestor to go with it. You can get it from www.hyderacing.com

FMF sells an insert. They say it will get it down to 96db, but that hasn't been my experience with that same pipe on my yamaha.

For my ktm, I run the stock silencer with the pro-moto billet end cap and spark arrestor. It reads 96 on the nose for every desert race or enduro that I do.

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I have the same exhaust and I bought the q-4 spark arrestor(at least I think that is what it was called) and it really reduced the noise with no noticable change in performance. I think the insert cost abount $30.

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db Dawgs are great for OEM exhausts but for aftermarket mufflers stick with the manufacturer's inserts and you'll have zero retention issues.

Repack the muffler and get a wash plug while you're at it.

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thats a spark arrestor, not gonna effect the sound at all

Sure it does. It also effects power.

Not only did I have this on my old 4.1, but I just had one put into my MRD system. And there's a noticeable difference in sound (much quieter), as well a noticeable difference in snap to throttle response. Less snap... Not as pipey.

... sounds to me that you've never had one, or tried one on a 4.1, if you had you'd know.

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many many over the last 45 years, every 4 stroke uses that type, had them in several PC cans, and my current FMF RCT can, I've run the sound tests at a few enduros too.

https://thumpertalk.com/forum/archive/index.php/t-614598.html

Sure it does. It also effects power.

Not only did I have this on my old 4.1, but I just had one put into my MRD system. And there's a noticeable difference in sound (much quieter), as well a noticeable difference in snap to throttle response. Less snap... Not as pipey.

... sounds to me that you've never had one, or tried one on a 4.1, if you had you'd know.

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many many over the last 45 years, every 4 stroke uses that type, had them in several PC cans, and my current FMF RCT can, I've run the sound tests at a few enduros too.

https://thumpertalk.com/forum/archive/index.php/t-614598.html

"every 4 stroke uses that type"

... they do? Not my aftermarket piped 450X. Which I've run both the FMF 4.1 and the MRD Racing exhaust. BOTH of them, WITH SA Insert installed are noticeably quieter... and noticeably lose snap off the throttle. In fact, when I would race desert, it's one thing I'd make sure to NOT have installed.

Maybe your speaking of something different?! 👍 I dunno... but, I'm specifically speaking of the item I posted a picture of. I'd love to show you the difference, see and hear for yourself. There's such a difference you don't need a "sound meter" to tell the difference of it installed, or not.

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