ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-14-2014, 04:12 PM   #1
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
KTM 625 SXC Muffler Modification & Repacking

KTM 625 SXC Muffler Modification & Repacking

I've just completed pulling apart my stock 625 SXC muffler. I took several pics of the process as I couldnít find anything on the web about it. Hopefully this helps other users to visualise whatís inside these things. Basically, there are two chambers, the first takes up about 2/3 of the length from the mid pipe, it has the perforated tube that is surrounded with a thick roll of packing. The second chamber is where the airflow gets restricted. The end cap has a tube that runs into the chamber but goes past the point where the air from the first chamber enters the second chamber. The pics below will help clarify this. Basically the airflow isnít direct, it has to circulate in the second chamber before exiting the end cap through a fairly small diameter tube.
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:13 PM   #2
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
I had watched a video where the guy tapped the lug out of the rivet with a punch and then drilled out the end of the rivet like this:

__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:13 PM   #3
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
I tried that, the lug popped out ok, but then I found that when I tried drilling the end off the rivet, it just spun with the drill bit. I found it a lot easier to just drill it first.
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:14 PM   #4
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
The end cap came off easily enough, if itís a bit stuck, try using a rubber mallet to gently tap around on the end cap to loosen it. When it came off, I could see that the rubber o-ring seal had broken and it looked as though someone had previously had it off as there was a bunch of red/orange silicone sealant.
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:14 PM   #5
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
This is what it looks like inside, as you can see in the pic the air enters this chamber through the top half of the pipe, and the tube running from the end cap extends beyond that point in the blank space below it. This chamber is about 8 inches deep.
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:16 PM   #6
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
I then followed the same process to remove the mid-pipe end cap. The perforated tube slid out easily with only a little persuasion as did the packing after it.


__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:16 PM   #7
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
In several videos Iíve watched I was surprised that the guys just use any old tape to secure the packing in order to slide it into the pipe, it looks the guy that did this one just used rubber bands.

__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:17 PM   #8
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
Now all that remains is to remove the plate that separates the two chambers. So I undid the small screws on either side of the pipe, inserted a rod with a folded up rag on the end, then tapped the rod on the ground and it slowly pushed the whole assembly out the top

__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:17 PM   #9
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
That end assembly is wrapped in a very thin layer of packing, I imagine purely to insulate the wall of the can against the gases circulating in the second chamber

__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 04:18 PM   #10
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
Many of you whoíve done modifications refer to the spark arrestor, there wasnít one on this bike and to be honest, Iím not fussed about having one. The laws here in Australia donít require it from what Iím aware of and dry dust doesnít really catch on fire too easily haha. So now Iím trying to figure out what to do to make the airflow a little less turbulent in the second chamber as I think the first chamber is fine as is. My Thoughts are to cut the tube coming from the end cap a lot shorter, this will allow less disturbance to the airflow. Is that all Iíd need to do? Iíve taken a pic so you can kinda see how the air circulates in this chamber.


__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 08:12 PM   #11
bmwktmbill
Traveler
 
Joined: Jul 2005
Location: Traveler
Oddometer: 4,939
Found it, I had to dig.

Scroll down.

http://advrider.com/forums/showthrea...=732362&page=3


This should help.

bill
__________________
'02 KTM 640 Adventure-lowered
"On the road there are no special cases."
Cormack McCarthy-The Crossing

The faster it goes the faster it breaks.
And high performance=high maintenance.
Bill Shockley

bmwktmbill screwed with this post 12-14-2014 at 08:18 PM
bmwktmbill is offline   Reply With Quote
Old 12-14-2014, 08:25 PM   #12
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
Thanks Bill, yeh I found that thread yesterday and referred to it in part, but the second chamber is different to mine, mine is the SXC Competition Muffler, Gunner's was the Supermoto one
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 08:36 PM   #13
motolab
Beastly Adventurer
 
motolab's Avatar
 
Joined: Feb 2006
Oddometer: 2,383
What is evident from the pictures, even though it is supposed to be a more performance-oriented muffler than the stock Supertapp, is just how restrictive it is relative to the Leo Vince.

Regards,

Derek
motolab is offline   Reply With Quote
Old 12-14-2014, 08:52 PM   #14
Young-Gun OP
KTM Tragic
 
Young-Gun's Avatar
 
Joined: Dec 2005
Location: Brisbane, AUS
Oddometer: 820
Quote:
Originally Posted by motolab View Post
What is evident from the pictures, even though it is supposed to be a more performance-oriented muffler than the stock Supertapp, is just how restrictive it is relative to the Leo Vince.

Regards,

Derek
Couldn't agree more, when I pulled it apart and saw the air-flow design I was surprised, I know I want to change it but I only get one chance at cutting as I don't know how to weld, so trying to get as much feedback as possible. I'm inclined to just chop off the tube that connects to the end cap and rivet it all back together, after replacing the packing of course...
__________________
Ryan
- - - - - - - - - - - - - -
KTM 950 'S' - Loving it!
KTM 625SXC - Adventure bike (project)
GPS and other items for sale
Young-Gun is offline   Reply With Quote
Old 12-14-2014, 09:01 PM   #15
thumper-darryl
Adventurer
 
Joined: Dec 2006
Oddometer: 90
Muffler

There is a ton of science with ex systems. Companies spend a ton of money designing these things. I have seen lots of modified mufflers that just make noise, but add no power. If you can find one that works to copy go for it.
thumper-darryl is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 08:26 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014