REPACK Arrow Exhaust/ 2009

So I opened my 2009 TE 450's Stock Arrow exhaust (power up type/when you have taken the Cat out) and found the core is 'contained" in a stainless shell. So to get to the actual packing= you have to cut welds and remove the stainless shell... its like there's a stainless exhaust covered by the aluminum outer shell.
I'll take some picks when I get a chance and then post them- I may completely remove that shell- leaving the endcaps- but it does add some strength to the system-

anyone else open one up for a repack??? I feel its long over due, but haven't seen this come up yet- Almost seems like I am cutting up a SM to get the cat out- but that was in the mid pipe on mine and long removed..... hmm turning into more of a project than I thought

How many miles do you have on your 09 te450. Was it getting loud or just felt it was time.

It has gotten louder- but it "should" be time- I bought it in March of 2009-I probably have 8000 miles or so... though have to guess at the miles since my OEM speedo died at one point and I went without for a good portion of a season before replacing with a Trailtech Vector-

Here's that pic:
You can see how the bottom portion slides into the aluminum casing. The rivets on the right go all the way into the stainless "inner casing" but the rivots do not go into the the stainless towards the end-cap(left)- that kinda complicates things when you concider the inner core is welded to the endcap (left) but the inner is only riveted on the right side...

I'll be grinding those welds tomorrow and determining how to proceed- the easiest would be to leave the welds on the left- opening the right and using loose packing rather than pillow type packing and then putting it all back together. But I think the aluminum is strong enough by itself. They may have this inner casing to work with the cat as further protection... But it doesn't seem necessary. I do have a welder- and stainless mig wire- so if needed I can re-weld or get creative.

Looks like quite the project. I saw a repacking vid on rocky mountain I think and it was nothing like that. They did it all from the LT rivets. Let us know how it goes and what welding needs to take place.

I did it last week, cut the pipe right by the welds. Cutting the welds will take forever and you will go thru a ton on wheels. The housing is very thin and you will be able to tack it back into place. You will have to cut both ends off to get at the packing. Reassemble, and slowly tack weld all the way around the can. If you have a belt sander after you have it welded up, use this to smooth out the welds and slide back into can. My two cans were a tight fit, very tight, so grinding them on the belt sander made them slide inside each other much better. Good luck.

Thanks Scott.
Here's what it looks like opened up:


mine had NO- absolutely NO packing- only the steel screen and steel wool that you see at the bottom. Yes there was evidence that there was fiberglass packing but only small patches (about enough to fill 1/4 of a sandwich bag)

This looks like a "normal exhaust" below... doesn't it. Pretty much what you'd expect when opening most exhausts. (now that RMATV/MC video is usefull- isn't it Jason!)
The inlet end cap on the right is welded to the core.
The core fits to the inner (2 piece) outlet endcap on the left. Then the inner is fitted to the outer endcap.
Then both endcaps are riveted to the aluminum outer casing. I see no reason to include the stainless "inner casing".
The insert on the bottom left is 'my db type killer' which has a spark arrestor screen on the end- its a little dirty right now.


So I will be able to repack like a normal exhaust just by cutting the welds off that "outer stainless casing" and carefully disassembling it.
These things don't like to come apart- there is sylicone at all the seams- a little heat helps. You have to be carefull not to crush the core or bend it on disassembly.
I used a block of wood and used the edge and a rubber mallet to bang it appart with "well thought out" swings after the rivets were taken out with a 3/16th drill bit.
The core is 15 inches- for refferance on packing materials. I plan to use stainless rivets just as it was originally= should be 3/16" .06"

Now I am ready to pack it... Originally, I had "thought" I would just add some leftover packing I had to what was there.... But there's nothing to add to really....
So I am going to order some immediately. Packing is pretty cheap depending on how you go about it. AND YES I know many use house insulation. There are many different kinds. Moose and FMF have nice kits with varying layers of mesh, screen, and Fiber which is what I have used in the past.

However- I have seen this company's stuff= made in the USA- and I think since I went though all this- I will go all out and get presumably some really good stuff.
Bristolcore....
I am really curious what this repack job will do to my DB. I think I will be pleased being that I had literally no packing in my exhaust. I realize that compared to most kits fmf/moose this is about 30 bucks more. But it is all inclusive and unless its just "great advertising" it is supposed to last/ made in USA is great too. Those mini pillows go in the endcaps. The core screen looks way better than I have seen, and the packing looks good as well.

http://www.bristolcore.com/default.asp



I'll report back when I get the stuff and finish the job. I have 2 more events this year comming up that require sound testing- curious to see how much of an improvement this makes.... Maybe I won't need my "db killer"... ok ok I know,. no need to get crazy...

So your going to ditch the inner SS casing? Seems it would be a normal exhaust after that then. That will make future repacking jobs much easier too. You gotta wonder though, why would they put it in there in the first place?

Yea, I wondered at first but everything structurally fits together without it-so it is not necessary to make any mods for the exhaust to be put back together= after grinding the welds and separating it. SO I'm ditching the stainless casing-I don't think its necessary. It certainly adds to the structure and resistance to crushing on crashes. I think they put it there because in the stock form- there was a CAT a few inches from it and they wanted to protect the aluminum- those cats get HOT. The stainless shell may be a detriment to the system in terms of containing heat (compared to aluminum)- which adds to the packing degrading at a higher rate. Its a theory anyway... I bet 2005-2007 Arrow Exhausts don't have this inner casing- Like most exhausts. The 2008 Arrow PU exhaust- may not have this shell= because the PU Pipe was never made to have a CAT. Whereas the 08 stock pip had a huge heat shield on the outside. The 09-10 came with this "convertible" Arrow PU w/o /or with CAT in one. I think the casing is for CATS.

So yes this will make repacking easier. The aluminum shell is pretty thick and resilient in and of itself. Its thicker than my old Ktm's exhaust was by far. Its also thicker than other exhausts I have had apart. I don't think I will miss the stainless shell. Basically it can only improve things- weight, easier to maintain... One could always put it back in.... but seriously we should repack exhausts yearly- If I had to cut/weld it once a year I'd get an FMF. Which doesn't have that stainless casing either. When its all said and done- I'll be the guinee pig- and I'll report back with Db values and any issues.

Thanks for sharing that information with us. I think you are right about the ss shield. I bet you can use the stock spark arrest-er in it and still be quieter than before. good luck and report back on the sound tests.

Well- I did two 130mile dual sport events since I repacked (stock 2009 Arrow/ in PU mode) as stated above.

Instantly I could tell my bike was much quiter- I believe more quite than ever... (I can really notice that floating rear disk chiming- which I usually don't hear)
At the first dualsport- they just waved me by and said they didn't want to test it since it was "good" they mainly wanted to test the "loud" bikes
At the 2nd dualsport- I was tested at 93db. (when my stock packing was newer I was at 95db) Had I done the test I would have seen it for my own eyes and would have liked to but-I trust their test- I know the guys, and they also said my bike was noticeably quieter.

Its hard to tell small amounts of power increase offroad with traction and such- but I felt a power increase I swear. Also, since it was noticeably quieter I think it didn't "seem" like I was wringing it out as much. My bike ran great though, better if anything. Flow is actually better with good packing- because otherwise flow fills the can and is pushed out rather than flowing straight trhough the core. Soundwaves are supposed to get dampened, absorbed, and bounced in the can not flow. Think of it as flow being greatest with a straight pipe, then a packed exhaust with core, then an unpacked exhaust with core.

I really liked the Bristol Core kit- it was very easy to use. I bought the 15 inch kit. I ordered it on a Sunday and got it standard shipping on Wednesday- which means they processed my order immediately- which is half the time it takes to receive orders quite often. The Stainless Core Wrap is high quality and easy to instal with there steel tie wraps, the pillow was awesome0 it was super tightly packed- once I wrapped it where I wanted then I pulled the tape strip and it stuck together perfectly and held throughout the installation. I used 1 encap pillow in the rear endcap the front one is enclosed so I didn't use the second one. I used permatex high temp silicone on the endcaps prior to closing it back up. I could not find stainless rivets the right size (3/16"/1/4") so I used aluminum- they have held fine but I might replace with stainless when I get them- might not need to though. The Pillow has a sturdy covering- the inside is lighter than the outside- but its like a kevlar weave. The threading that creates the seams in the pillow is supposed to release with heat so that it fills the exhaust consistently. Packing needs to have a few heat cycles and a few hours to reach its full potential. This packing is supposed to last longer- I believe it but when the time comes I'll use it again.

Also- if anyone opens up these exhausts- I'd definately leave that stainless inner casing out- it is not necesary and I believe leaving that out will increase the life of your packing. I assume that stainless inner casing is because in Stock form they have a cat. I assume anyone who opens up their exhaust does not have a CAT. Also its probably minimal- but there is a weight savings but more importantly- it will be MUCH MUCH easier to repack once that stainless inner shield is left out. Generally, we should repack once a year- but if you are sound tested- you should have a baseline and when your bike starts getting louder you know its time to repack. LESS DB=MORE TRAILS

Thanks for the report and pic's. I rode my 08 a few days ago and the sound note and volume in general just dosn't sound good anymore so I think its time to do mine also. I'll have your thread as a guide now.

Yeh Brad, when you pulled away from one of the hero sections at the big woods I thought to myself that your bike was pretty loud. Good to hear that the packing help get the db down. You have any rides that your going to do coming up?

I repacked my muffler on my 09te310. Every thing went exactly like the post said and now i can hear my intake more and the bottom feels a little stronger too. Thank you HUSKYnXJnWI .

What diameter is that arrows perforated tube?

And did you weld that "inner" endcap to it?

I did not measure the core- it tapers down a little towards the outlet. Maybe from 2.25" down to 2.00"~~???

I did not weld anything- the inlet endcap is welded to the core, the outlet is not welded- but the core fits into the "inner" endcap with little gap so its fitted (it can't go anywhere)- its purpose is only to give flow a direction- so its not structural. You have to be somewhat carefull not to dent/bend/tear/damage it upon assembly or disassembly. If it were welded to the "inner end cap" it would changed the way you'd assemble/disassemble and you'd have to slide that endcap though the entire shell- this would add to the chance you crush or bend the core at some point.

Yepyep, I was just comparing to what I did few months ago, when took stuff out from stock SM510 cans...

Thinking about changing a smaller tube inside to get more packing->less noise.
Now it's 50mm(2")

Hey how's yous packing holding up? Any issues with strength without the inner core with get offs? I'm going to do mine now. It's well past time.

no issues to report- still would do it the same way. The stainless shell is not necessary. I would use the bristlecore kit again as well.

Great write up did you happen to weight the steal sleeve that you removed. curious to know how much lighter it ended up. I haven't even started riding my bike yet and I am already disappointed by how much louder this bike is compare to my Yamaha. Hopefully I don't end of needing an aftermarket exhaust to quite it down. With do sound test with RPM in the next coming months.

Yup my 08 does not have the gigantic steel shell. I ordered the Bristol kit which is double the price of others. It does look like its more complete of a kit though.

After taking mine apart tonight I'm doubting even repacking. What made you guys decide to repack, noise, condition or time?

For starters, this piece is welded to the inner core. Would it have to come off?



Secondly, this packing looks good to me. None missing and quite clean.



What do ya think?