My little XT came with an FMF Powercore 4 exhaust. It is a nice throaty sound but is mind-numbingly loud. I've got two different kinds of glass packing material but they both oscillate around in there so much that the material disintegrates in about 50 miles. Any ideas how to make the packing hold up? I'm tempted to buy another stock assembly but would rather figure out a way to make some packing work. Please advise if you can.
Thanks,
kdt
Only time I ever repacked a can was a pita!
Had to drill the rivets out, remove the cone and core.
I used some packing off eBay, rewraped in one direction, laced tiewire around it, then added another 2 layers and tie wired that to keep it tight.
It worked well, and dampened the sound quite a bit. Then I inherited a new exhaust and passed it on later.
I think I'm facing the same problem. The cone comes out with one screw. Then there is about a 1.5 in hollow perforated tube inside the core...which is where I've been shoving the packing in that subsequently self destructs. To get the core out and properly wrap the outside of it will require a bunch of drilling and banging and it will probably look like crap when I'm done.
I sure wish I could find a way to construct a sturdy insert for the hollow part. I watched a video of the official FMF quiet core insert last night. I couldn't tell any difference at all with their quiet core insert. It's just a stainless hollow tube that sticks about 1/4 the way up in the hollow core with no additional dampening material....useless.
LOUD PIPES SAVE LIVES!!!! ;D
Sorry man, I couldn't help myself.
Quote from: lazeebum on May 04, 2016, 06:39:44 PM
LOUD PIPES SAVE LIVES!!!! ;D
Sorry man, I couldn't help myself.
Loud pipes make me hungry for Valium biscuits and scotch gravy.
I used stove rope and wand it round the baffle. Tied each end in place with stainless steel wire. Same rope used for oven gasket material. Comes in different diameters.
I found when doing my zrx exhaust if you wrap it as tight as possible (to the point of having to almost hammer it in there) it stays alot longer...
Quote from: IceCold4x4 on May 07, 2016, 06:57:07 PM
I found when doing my zrx exhaust if you wrap it as tight as possible (to the point of having to almost hammer it in there) it stays alot longer...
Well...I just finished an experiment doing almost exactly what you said. I used a screen from an automotive air filter to wrap the glass.
Interestingly, one of the largest filters on the shelf was one of the cheapest....must be for a Chevy or Ford truck.
(http://i556.photobucket.com/albums/ss4/kdtrull/2016-05-07%20Sante%20Fe/20160507_181721_zpsvb1d2kqv.jpg) (http://s556.photobucket.com/user/kdtrull/media/2016-05-07%20Sante%20Fe/20160507_181721_zpsvb1d2kqv.jpg.html)
Giant, hollow, obnoxious "muffler":
(http://i556.photobucket.com/albums/ss4/kdtrull/2016-05-07%20Sante%20Fe/20160507_182110_zpsxf7tmhz8.jpg) (http://s556.photobucket.com/user/kdtrull/media/2016-05-07%20Sante%20Fe/20160507_182110_zpsxf7tmhz8.jpg.html)
Scooter joint....now chill, loudmouth:
(http://i556.photobucket.com/albums/ss4/kdtrull/2016-05-07%20Sante%20Fe/20160507_182323_zps9u0fxlhi.jpg) (http://s556.photobucket.com/user/kdtrull/media/2016-05-07%20Sante%20Fe/20160507_182323_zps9u0fxlhi.jpg.html)
(http://i556.photobucket.com/albums/ss4/kdtrull/2016-05-07%20Sante%20Fe/20160507_182727_zpsc8k7zlrh.jpg) (http://s556.photobucket.com/user/kdtrull/media/2016-05-07%20Sante%20Fe/20160507_182727_zpsc8k7zlrh.jpg.html)
http://vimeo.com/165722046
I think the phone is normalizing the volume...it is quite a bit quieter...although you can't tell that much in the video.
I'll pull it after tomorrow's ride and see how it survives.....hopeful but not optimistic.
Keep hope alive!
kdt
the packing goes around the outside of the hollow tube...
Quote from: IceCold4x4 on May 07, 2016, 07:21:14 PM
the packing goes around the outside of the hollow tube...
Yeah...this is meant to be a workaround. I've already tried to pull it apart to get to the outside and almost destroyed it....the other end has about 40 pry marks all the way around the outer shell.
Quote from: kdtrull on May 07, 2016, 07:23:35 PM
Quote from: IceCold4x4 on May 07, 2016, 07:21:14 PM
the packing goes around the outside of the hollow tube...
Yeah...this is meant to be a workaround. I've already tried to pull it apart to get to the outside and almost destroyed it.
ah ok.... lol for a second there i was wondering.
I would much rather do it like you had in mind but I pulled all the screws (no rivets) but there is some kind of silicon goo between the core and the shell. I pulled, beat, banged, and pried....it would not let loose and I was really making a lot of cosmetic damage.
Edit: Actually, the outboard end IS rivets. I was trying to disassemble from the inboard end. Maybe I need to drill the rivets and go at it from the outboard end???
Putting the packing in the center of the pipe can cause to much back pressure from blockage and burn a valve.
Quote from: Chuck A. on May 07, 2016, 08:04:01 PM
Putting the packing in the center of the pipe can cause to much back pressure from blockage and burn a valve.
Yep....I monitored flow for that. I still have way more flow than the stock pipe. Also....the last inch or so of the flow path is unobstructed because the spark arrestor sticks about 3 inches up into the pipe. All the glass would have to blow out of the makeshift pack and jam up around the arrestor to really cut the flow.
I don't imagine you will have much different results with what you have done. You should take the cap off the exit end. The inlet end should be sealed on. Hence the reason you can't get il off.
I have seen people use heavy grade steal wool to pack with also.think like a kitchen scrubber. I don't know where they got it, but it was from an industrial job site.
Quote from: LawnmowerRG on May 08, 2016, 12:19:25 PM
I don't imagine you will have much different results with what you have done. You should take the cap off the exit end. The inlet end should be sealed on. Hence the reason you can't get il off.
I have seen people use heavy grade steal wool to pack with also.think like a kitchen scrubber. I don't know where they got it, but it was from an industrial job site.
I think you're right. I've only been out a few hours and the new pack is all but gone. I do have a pack of those copper colored heavy scouring pads I may try next.
I would not use steel wool of any kind. Even heavy coil industrial.
It can catch fire....
I'm about to just start looking for a stock muffler. :'(
I've seen steel wool burn before...it's kinda pretty....wouldn't want it burning in my exhaust though.
Failure:
(http://i556.photobucket.com/albums/ss4/kdtrull/20160509_163718_zpskabca0fx.jpg) (http://s556.photobucket.com/user/kdtrull/media/20160509_163718_zpskabca0fx.jpg.html)
I give. I don't want to drill the rivets. Maybe I can sell or trade.
Quote from: kdtrull on May 09, 2016, 05:15:50 PM
Failure:
(http://i556.photobucket.com/albums/ss4/kdtrull/20160509_163718_zpskabca0fx.jpg) (http://s556.photobucket.com/user/kdtrull/media/20160509_163718_zpskabca0fx.jpg.html)
I give. I don't want to drill the rivets. Maybe I can sell or trade.
Wrap as much fiberglass mat around the tube that will fit in the can and safety wire it down tight. That's what I have done in the past and it has always lasted.
Baffles are to absorb sound. Packing goes around the outer side off the baffle. Packing the middle of the tube blocks air flow. Engine is gonna heat up fast. Best of luck.
Quote from: Chuck A. on May 10, 2016, 08:24:45 PM
Baffles are to absorb sound. Packing goes around the outer side off the baffle. Packing the middle of the tube blocks air flow. Engine is gonna heat up fast. Best of luck.
I hear ya' man....I was just looking for a quick fix. There was, at least, two axial inches of unobstructed flow path. I don't want to drill the rivets in case I decide to sell it. I'll just live with it for now. There's not a lot of XT250 folks out there that want their brains scrambled by an almost full open exhaust. It is, after all, a mammoth 249 cc's of expandable gas exploding out the pipe! ;D
Don't forget, I rode a lot of miles into North Georgia behind that bike. That's one tough machine! :o ;D
I repacked the FMF pipe on my TTR 250 which I think is pretty close to the one on my dad's XT250. I came at it from the engine side of the muffler instead of the end. I unhooked the core from everything connecting it to the tail of the pipe and then pulled it all apart from the rear. It was a pain in the rear to pull out but once I did I was able to wrap the core tightly in the packing and slowly work it down using light taps of a hammer and the sheer force of will of 2 200lb men. The process involved removing the exhaust pipe short of the header and may be more effort than you deem worth but it worked for me. Best of luck fixing you XT. That may be the world's most practical adventure bike!
Quote from: bblass on May 11, 2016, 09:57:59 AM
I repacked the FMF pipe on my TTR 250 which I think is pretty close to the one on my dad's XT250. I came at it from the engine side of the muffler instead of the end. I unhooked the core from everything connecting it to the tail of the pipe and then pulled it all apart from the rear. It was a pain in the rear to pull out but once I did I was able to wrap the core tightly in the packing and slowly work it down using light taps of a hammer and the sheer force of will of 2 200lb men. The process involved removing the exhaust pipe short of the header and may be more effort than you deem worth but it worked for me. Best of luck fixing you XT. That may be the world's most practical adventure bike!
That's good info. I may try it again. On the first attempt, last Summer, I took it off, removed all the hex screws from the inboard end, and pulled, pried, banged, and cussed until I gave out. It never budged. In the places where I pried enough to bend the outer casing, it looked like there was some kind of sealant in there....which I think is why it never broke loose. I may have the weight of two men but, apparently, the strength of a fair maiden. I do, however, have lots of trees, some rigging slings, and a cable wench!
There was a little sealant in there now that you mention it; and I want to say a black gasket. We hit it with the heat gun for a solid minute or two. Sorry, had blocked that evil out of my mind until you just mentioned it.
Looked up some videos on the FMF and it appears to be that you do pull the Q4 for the inlet side. I have never packed an FMF exhaust.
I have seen steel wool burn. Used it to start camp fires in fact. I dont think the stuff I saw the guy use would burn easily, but I don't ever remember seeing the guy again either. So he may have gone out in a ball of flames.
Quote from: LawnmowerRG on May 15, 2016, 12:47:48 PM
Looked up some videos on the FMF and it appears to be that you do pull the Q4 for the inlet side. I have never packed an FMF exhaust.
I have seen steel wool burn. Used it to start camp fires in fact. I dont think the stuff I saw the guy use would burn easily, but I don't ever remember seeing the guy again either. So he may have gone out in a ball of flames.
Well, I wasn't going to mention it but....I used steel wool in my first '08 XT250 after I drilled out the stock baffle plate on the inboard end of the can more than I bargained for. It never caught fire but I guess it could have??? It worked good but I suppose it is asking for trouble.
Here's the deal on XT mods in my experience....just for anyone who might stumble into this territory in the future....intake and exhaust mods, in my experience, have never made a hill of beans worth of difference on the XTs I've had. They run how they run....and that's about it, AFAIK.
Replacing the clutch plates and springs is the only thing I've ever done to one that had a significant positive impact.
It shouldn't be that difficult. I must be missing something. I've repacked FMF cans many times with no issue. It's bolted together. You don't have to drill out any rivets. just unscrew it and after a few love taps it comes apart. If it's been neglected or if it's dented it may take some harder swings from a dead blow hammer.
Here is the full procedure for an FMF Powercore 4
https://www.youtube.com/watch?v=5WituZdypNc
Quote from: Mulley on May 16, 2016, 02:56:08 PM
It shouldn't be that difficult. I must be missing something. I've repacked FMF cans many times with no issue. It's bolted together. You don't have to drill out any rivets. just unscrew it and after a few love taps it comes apart. If it's been neglected or if it's dented it may take some harder swings from a dead blow hammer.
Here is the full procedure for an FMF Powercore 4
https://www.youtube.com/watch?v=5WituZdypNc
I'll try again when I have more time.and new pack of stuffin. Thanks for diy video.