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Shawn Powell
03-03-2017, 01:36 PM
I did this on a 350x system. My DG was bought new and is way too loud and seemed to have zero back pressure killing bottom end. So purchased a turn down and quiet core for a HMF muffler. Took my DG apart , repacked it with FMF 4 stroke packing (much heavier) cut the HMF core in half(was way to long for the DG ) and installed it in between my DG can and the HMF turn down. Takes the outlet diameter from 1 5/8" to 1 3/8". This dropped my decibel reading from 104 db to 93. Also greatly improved my bottom and midrange. Still sound great looks nice and runs better. Don't know if anyone is interested but I like it. Runs better than my supertrapp. https://uploads.tapatalk-cdn.com/20170303/9cb7180d0f402cd61d947fb661de4145.jpg


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Ranvier
03-03-2017, 05:16 PM
Hey that's a sweet setup. There so few options for the 350X and the DG is annoyingly loud.

350for350
03-03-2017, 09:50 PM
I'd say that you did great! 93 db is WAY better than 104! I have a friend who bought a 2002 Raptor with a White Bros. exhaust a few years back. The first time I rode it, I told him to dig a deep hole and bury that POS exhaust! It was very loud. I can't stand the sound of an extremely loud four stroke. Maybe that's why I don't ride a Harley.

Shawn Powell
03-03-2017, 11:11 PM
Thanks. Yeah the noise alone was worth the extra few bucks for the tip and core. But it also runs better. Hard to tell if it affected top end. I doubt it it's a mild motor. But mid range WAY better. The DG is just terrible loud. I might custom build one this summer once it's too hot to ride every weekend. But I might not now.


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shindig
03-04-2017, 12:22 AM
Nice. I need something similar for my 200x. The DG exhaust is too loud and not sure what to do. I hate even kicking it over at home, because I feel like I'm going to annoy my neighbors. Do you have detail instructions of how you did this?

Ranvier
03-04-2017, 12:24 AM
You have any pictures of the process? I have dgs sitting as I went back to stock

Shawn Powell
03-04-2017, 12:38 PM
Nice. I need something similar for my 200x. The DG exhaust is too loud and not sure what to do. I hate even kicking it over at home, because I feel like I'm going to annoy my neighbors. Do you have detail instructions of how you did this?

I didn't take pictures but I can walk you through it. I'm out of town this weekend but let me get home and I'll add some pics and better directions to the post.


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shindig
03-04-2017, 02:58 PM
I didn't take pictures but I can walk you through it. I'm out of town this weekend but let me get home and I'll add some pics and better directions to the post.


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Thank you Shawn. Love those 350x's. My younger bro has an 86 he restored. Still the hardest bikes to kick over...lol. Here's his from last Fall at Finger Lakes ATV park, before it got caked in mud:)

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shindig
03-04-2017, 05:15 PM
Here's a pic of my DG exhaust, I bought it less than a year ago, before had a Cobra, which was even louder. I don't see how to take it apart?

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Shawn Powell
03-04-2017, 05:31 PM
Thank you Shawn. Love those 350x's. My younger bro has an 86 he restored. Still the hardest bikes to kick over...lol. Here's his from last Fall at Finger Lakes ATV park, before it got caked in mud:)

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There's a trick for the 350. Unfortunately every bike has its own trick haha. Mines nice and easy now. Slowly all the way down up 4 clicks and jump it.


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Shawn Powell
03-04-2017, 06:54 PM
Here's a pic of my DG exhaust, I bought it less than a year ago, before had a Cobra, which was even louder. I don't see how to take it apart?

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You have to drill out those rivets that hold the DG plate on. Then there's a snap ring that holds the can inside the housing. I used a very small flat screwdriver to kinda pry it out and grabbed it with some needle nose pliers. Then mine has a large Phillips machine screw on the bottom. Remove all that and the inner tube and packing will come out.


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shindig
03-04-2017, 07:33 PM
Thanks again Shawn. If you decide to do a write up and parts needed, I will have some Kansas City BBQ delivered to you. I am completely serious. Great job innovating and not just accepting that your exhaust will be loud and live with it. Kudos!

Kevin

Shawn Powell
03-04-2017, 10:47 PM
Thanks again Shawn. If you decide to do a write up and parts needed, I will have some Kansas City BBQ delivered to you. I am completely serious. Great job innovating and not just accepting that your exhaust will be loud and live with it. Kudos!

Kevin

I'll show mine when I get home this week. Also I have a 5 $ spark arrestor mod for that pipe at the same time. Need them here in California.


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350for350
03-04-2017, 11:01 PM
You actually need a spark arrestor a lot of places. Every national park that I've been requires them. That's why I like to put one on in the first place if I can.

Shawn Powell
03-05-2017, 12:41 AM
You actually need a spark arrestor a lot of places. Every national park that I've been requires them. That's why I like to put one on in the first place if I can.

Go to Home Depot and buy a stainless steel sink strainer. 3-4$ and when I post up pictures on the mod I'll show you how I did it.


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ironchop
03-05-2017, 12:54 AM
Nice mods. I hate those DGs. I don't even know why they put a screen in them like that will slow down soundwaves thru a 2 inch hole straight through it. It's a resonator.

Thanks for the disassembly tip too. Clever hide behind the tag.

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lafayette350x
03-17-2017, 02:46 PM
Nice mods. I hate those DGs. I don't even know why they put a screen in them like that will slow down soundwaves thru a 2 inch hole straight through it. It's a resonator.

Thanks for the disassembly tip too. Clever hide behind the tag.

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I just copied this and ordered the quiet core for the HMF and ordered the packing for the FMF. Hope it's as easy as you guys say.

Shawn Powell
03-17-2017, 03:17 PM
I just copied this and ordered the quiet core for the HMF and ordered the packing for the FMF. Hope it's as easy as you guys say.

I'm gonna do a tear down with pics hopefully Sunday. While your waiting go buy a stainless steel sink screen from Home Depot. Like 5$. We'll build you a spark arresstor.


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Ranvier
03-17-2017, 03:46 PM
Let us know how it goes. I want to try this.

x-rider
04-16-2017, 01:53 PM
Any updates on this. A build thread would be awesome.

Ranvier
04-16-2017, 02:11 PM
Last time I was checked, they wanted to see the usfs approved spark arrestor stamp which my supertrapp has.

That said, I still want to do this mod once the other x is running for noise reduction.

Shawn Powell
04-16-2017, 03:49 PM
Any updates on this. A build thread would be awesome.

I'll do a quick tear down with pics maybe this week. Been busy with riding and work. Also 3 kids.


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Shawn Powell
04-16-2017, 07:11 PM
Last time I was checked, they wanted to see the usfs approved spark arrestor stamp which my supertrapp has.

That said, I still want to do this mod once the other x is running for noise reduction.

I just went to a park run by rangers who check. He looked did the stick test and said "nice three wheeler. HAvent seen one that clean in a while. Have fun"


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Ranvier
04-16-2017, 08:32 PM
I just went to a park run by rangers who check. He looked did the stick test and said "nice three wheeler. HAvent seen one that clean in a while. Have fun"


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How many decibels?

Shawn Powell
04-16-2017, 10:42 PM
How many decibels?

95 db


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Shawn Powell
05-29-2017, 03:22 PM
So this is a long over due. I tore this down to replace my spark arrestor ( had a ranger question placement apparently it needs to be after the packing. Mine was In front. He still let me pass through and ride. Just asked me to fix it before I came back) so here we go with pics
https://uploads.tapatalk-cdn.com/20170529/a4c431a9e02bef899412e23f28816261.jpg
Drill these rivets out there 1/4"
https://uploads.tapatalk-cdn.com/20170529/be0130c2b43794d9c8bae221895d08b6.jpg
Remove plate
https://uploads.tapatalk-cdn.com/20170529/8f4ecc2ecb240b1fdaa222d1738e4f1e.jpg
Remove set screw
https://uploads.tapatalk-cdn.com/20170529/9a83825f4043c3662dd4635d23cd5512.jpg
There's a c clip buried in there holding muffler body in. I use a small flat screwdriver to pop it out and grab it with pliers
https://uploads.tapatalk-cdn.com/20170529/0d3a6c39719f61874b5988d0010e0fef.jpg
Pull body out. You can see where I put my old spark arrestor. That's a 5$ sink strainer from Home Depot molded to fit. Worked fine but I guess it's supposed to be AFTER the packing. I never knew. Had a lot of ranger look at my bike and never question it. No big deal. Move it to the other end. I owe 3ww a build thread anyways.
https://uploads.tapatalk-cdn.com/20170529/3ee99ff19d9025067cfa579932e99737.jpg
https://uploads.tapatalk-cdn.com/20170529/bff6a5eaa41a60eb2803f0b6439eac77.jpg
You can see how I back bolted the turn down through the body. The quite core is sandwiched in between the body and the turn down
https://uploads.tapatalk-cdn.com/20170529/f6232464294fb6e6a7a720166b0ee8e5.jpg
Here's the quiet core. I had to cut it down to about 3" It was longer than the muffler body when I got it. HMF said it should be about 40% of the muffler body length. 3" seems fine.
https://uploads.tapatalk-cdn.com/20170529/d08384823be0d753ec75ddeeaf4ce2bc.jpg
Here's my new HMF legal spark arrestor quiet core fits under that. All gets wedged under the turn down. This is all bought from HMF off amazon ,quiet core turn down and spark arrestor ,for about 50$
https://uploads.tapatalk-cdn.com/20170529/520127bfc4a75255d9f8e978f0d64a12.jpg
Reverse process. Ride and enjoy your now forest legal DG exhaust. On heavy modded machines I wouldn't run the core. Always spark arrestor and turn Down. It reduces the flow from 1 5/8" to 1 1/4". That's a lot! It did put a damper on my top end but gave me bottom end grunt.
Next year I'm going to do a 400ex header and a FMF q4 muffler. This is temporary but works well and sounds good.


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Shawn Powell
05-29-2017, 05:39 PM
Also this has nothing to do with this mod but does concern this exhaust. I have been getting a leak at the header to muffler connection. With DG there is no gasket there and with the aluminum system there is no clamp. Friction fit. Well after 1500 miles(that's verified via gps) and 2 years it's a bit loose. I tried bronze silicone burn right up. So I made two 3/4" long slits with my dremel and bought a Hose clamp to crush it down. Also used black silicone this time. (700 degree) we will see how time takes it. But hisnis how my 400ex connection is and doesn't leak after 15 years. Enjoy. https://uploads.tapatalk-cdn.com/20170529/ff9fb38385300def72f11fa490753234.jpg


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350for350
05-29-2017, 07:06 PM
Thanks, Shawn. Very informative.

Ranvier
05-29-2017, 07:25 PM
Thanks for the pics and info. Will try it.

x-rider
05-30-2017, 10:56 PM
Sweet tip. I may try this mod. Thanks for sharing.

shindig
01-16-2018, 11:54 PM
I lost track. I was searching for this thread and then I thought you had switched to a SuperTrapp? I can't decide if I should do this mod for my 86 200x or the universal Supertrapp. Thoughts? Thanks!

Kevin

Shawn Powell
01-17-2018, 02:19 AM
I lost track. I was searching for this thread and then I thought you had switched to a SuperTrapp? I can't decide if I should do this mod for my 86 200x or the universal Supertrapp. Thoughts? Thanks!

Kevin

I ended up switching over to a universal SupertrApp. Kept my dg pipe as it’s larger than the OEM, had a custom mid pipe bent and used a 1.75” SupertrApp and have ended up at 10 plates. Runs great sounds ok and much quieter than the dg even with the baffle. Baffle I made was definitely cheaper. Good luck. https://uploads.tapatalk-cdn.com/20180117/d24e6099602ef5ea849ec99ee73b8a07.jpg


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lndy650
01-17-2018, 03:11 AM
cool mod for an otherwise garbage pipe. i despise dg exhaust. not even gonna capitalize dg lol

shindig
01-17-2018, 10:26 AM
I ended up switching over to a universal SupertrApp. Kept my dg pipe as it’s larger than the OEM, had a custom mid pipe bent and used a 1.75” SupertrApp and have ended up at 10 plates. Runs great sounds ok and much quieter than the dg even with the baffle. Baffle I made was definitely cheaper. Good luck. https://uploads.tapatalk-cdn.com/20180117/d24e6099602ef5ea849ec99ee73b8a07.jpg


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Ok, that's what I thought. If I order the SuperTrapp, do you know the size I would get for a 2nd Gen 200X? Also, did you take your bike in to the muffler shop or just have them add the mid pipe? I don't know what to do...lol.

Shawn Powell
01-17-2018, 01:55 PM
Ok, that's what I thought. If I order the SuperTrapp, do you know the size I would get for a 2nd Gen 200X? Also, did you take your bike in to the muffler shop or just have them add the mid pipe? I don't know what to do...lol.

I think 1.75 was the smallest one they made. I would think whatever your head pipe is do that or the next size up. My dg header was 1 5/8” so made sense. And I took the whole bike to the muffler shop. They bent it up with a piece of stainless in about 20 minutes for 30$. I wrapped my whole system in black fiberglass exhaust wrap also. Covers up any ugly spots.


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shindig
01-17-2018, 04:31 PM
I'm wondering if I could just cut the DG exhaust end off and clamp the SuperTrapp exhaust over the steel mid section and then have the bracket welded to the exhaust. Or just do nothing...lol.

lndy650
01-17-2018, 05:45 PM
Could just use a supertrapp pipe? or find like a yoshi or duncan for pretty much any 350-450 atv and make it work. you can make almost any silencer fit and look good with the right tools and ingenuity

shindig
01-19-2018, 12:16 PM
Hey Shawn, on the DG conversion, what is the diameter of the turn down on your 350X? I'll have to check my 200X when I get home, but not sure if they are the same diameter or not. So to do all this, I need the HMF turn down (not sure what size, but looks like on Amazon they are all the same size), HMF quiet core and FMF 4 stroke packing? And then I can buy or build a spark arrestor?

Thanks again.
Kevin

Shawn Powell
01-19-2018, 02:45 PM
Hey Shawn, on the DG conversion, what is the diameter of the turn down on your 350X? I'll have to check my 200X when I get home, but not sure if they are the same diameter or not. So to do all this, I need the HMF turn down (not sure what size, but looks like on Amazon they are all the same size), HMF quiet core and FMF 4 stroke packing? And then I can buy or build a spark arrestor?

Thanks again.
Kevin

I think it was about 3.5” , not sure and it’s packed away in the rafters. And there was only one size hmf turn down when I did mine. With that same stuff on amazon hmf has a spark arrestor for that setup if you wanna save some time. https://uploads.tapatalk-cdn.com/20180119/36dd0451fbfc18d9372b5ab02e5d4384.jpg

Link
https://www.amazon.com/gp/aw/d/B00JXLPTCG/ref=mp_s_a_1_7?ie=UTF8&qid=1516387441&sr=8-7&pi=AC_SX236_SY340_QL65&keywords=hmf+turn+down&dpPl=1&dpID=51zgkPsIczL&ref=plSrch
This is what I bought to do the whole thing. I would bet dg uses the same can for all the models.


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shindig
01-19-2018, 06:33 PM
Thanks again Shawn. I ordered those 3 up above plus the 4 stroke packing. Came to $92, but I had $32 in Amazon points, so really $60. When I get everything and start the process, I'll probably have some questions. Appreciate your insight. Most parks around here don't require a spark arrestor, or they just turn a blind eye. My 250R has the OE exhaust I had ceramic powder coated, so it's pretty quiet and has a spark arrestor.

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Kevin

shindig
01-24-2018, 11:00 AM
So I got the HMF end cap and spark arrestor yesterday, still waiting on the quiet core and packing. Of course, on the 200x's, the end diameter is smaller than the 350x's, so the end cap won't fit inside the body, probably an 1/8 to 1/4 too wide. So now not sure what to do. I guess I could just bolt it on, it wouldn't sit inside the body. Nothing is ever easy. I can't seem to find any others. Do I need the end cap when putting everything back together?

Kevin

Shawn Powell
01-24-2018, 11:14 PM
I used the end cap to sandwich the core and spark arrestor in there. By the time you get the build up of the two you might be ok , maybe a washer for a spacer. The only issue i see with that it how to get the c clip re installed that hold the muffler into the actual body. Maybe shave that 1/8” off the outer diameter of the end cap?


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shindig
01-24-2018, 11:24 PM
Yeah I might have to trim down the end cap, maybe using my grinder. I got the rest of the parts, so I might mess with it this weekend. For the packing, did you just remove the original and re-wrap it? I'll probably understand it more once I get it taken apart. I do have an aluminum Coba exhaust I might experiment on first, but it's over at my brothers house right now.

Thanks,
Kevin

Shawn Powell
01-25-2018, 12:21 AM
For the packing yes, when I took mine apart the dg packing was like feathers. Super light weight and soft. I’ve repacked my white brothers once and I remembered the the FMF stuff I used was way heavier than that so I did that. Made a difference but again with almost zero back pressure it doesn’t really work , enter baffle idea.


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shindig
01-25-2018, 02:39 PM
Ok, so the c ring holds everything in. I thought it was maybe the small screw at the bottom. After you drilled out the rivets, looks like you put new rivets in? Guess I'll have to stop at the hardware store and pick up a pop rivet gun..lol. Never needed one before, but you never know.

Kevin

Shawn Powell
01-25-2018, 04:41 PM
Ok, so the c ring holds everything in. I thought it was maybe the small screw at the bottom. After you drilled out the rivets, looks like you put new rivets in? Guess I'll have to stop at the hardware store and pick up a pop rivet gun..lol. Never needed one before, but you never know.

Kevin

All of it does, the screw sets it and the c ring hold the can, the rivets also help ,can’t pull it out while they exist. Make sure you buy a large pop riveter , those are 1/4”. I got a cheap one at harbor freight for this project , was like 19$ and came with a bunch of rivets.


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shindig
01-26-2018, 10:00 PM
Hey Shawn, finally got the DG apart. Here are the pics. So I cleaned up the mesh thingamagig :) and it looks like I don't need to cut my quiet core, it drops right in. Next I place the spark arrestor on top. Did you bolt yours down or back bolt everything including the turn down? Messing with this when I should be resting since I have a cold, but I'm sick of doing nothing...lol.

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Shawn Powell
01-26-2018, 10:05 PM
You don’t want the quiet core more than 1/3 of the way down the muffler. The hmf this is made for is much longer than the dg. You want it to hit and create pressure to push it into the new packing to muffle the sound.
And I just drilled some holes and used some stainless hardware and nylock nuts. But yeah your on the right path.


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shindig
02-13-2018, 07:57 PM
Well finally got this done, thanks for your help Shawn. I had to go with a Supertrapp end cap, the HMF turndown was too wide for my DG. I had to put the spark arrestor on the back, I know you mentioned it was supposed to be forward, but it wasn't working with the type of endcap I had. Also wrapped the header with ceramic heat wrap, painted the wrap with hi heat silicone paint and installed a universal heat guard. It's "slightly" quieter, but oh well, I haven't messed with it much since installing. Few pics!

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Shawn Powell
02-13-2018, 10:43 PM
Looks good. Maybe my pipe is larger diameter because I have the aluminum model? I did the same to my header, heat wrap and shield. I did not paint it though...... give an update to how it lasts after riding. Cause mines looks not so beautiful anymore. That’s a great looking trike.


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shindig
02-14-2018, 12:08 AM
Looks good. Maybe my pipe is larger diameter because I have the aluminum model? I did the same to my header, heat wrap and shield. I did not paint it though...... give an update to how it lasts after riding. Cause mines looks not so beautiful anymore. That’s a great looking trike.


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Thanks, it doesn't get ridden much.

Tom12254
01-13-2023, 11:28 AM
Well finally got this done, thanks for your help Shawn. I had to go with a Supertrapp end cap, the HMF turndown was too wide for my DG. I had to put the spark arrestor on the back, I know you mentioned it was supposed to be forward, but it wasn't working with the type of endcap I had. Also wrapped the header with ceramic heat wrap, painted the wrap with hi heat silicone paint and installed a universal heat guard. It's "slightly" quieter, but oh well, I haven't messed with it much since installing. Few pics!

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250193

Waking up a 4 year old thread here but I found this to be a super helpful way in making the DG quiet for low cost. I ran into the same problem with the HMF end cap being "too big" for the DG but I think the actual problem is they sell 2 models of the HMF end cap a 3 bolt and a 4 bolt. If you buy the 4 bolt it will be too big as it's a bigger version. The 3 bolt should fit just like the OPs. (Looks like from the pics he's using the 3 bolt) I have one ordered so I will update if that's in fact the case and it fits just for future reference.