Two Stroke Motocross
Two Stroke Motocross Forum => Technical => Topic started by: Coop on May 04, 2010, 06:37:03 AM
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I did a search and didn't find anything, so sorry if this is a repost. I would like to repack the silencer's on both mine and my nephew's bikes (1988 KX125, 1997 CR80 Expert).
I am just curious what everyone is using and much you pay. In a google search it seems more people are recommending regular pink house insulation, but I am skeptical. I have used FMF in the past and it's what the local shop carries but of course they are sold out right now, LOL.
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I'm pretty sure the pink house insulation will come out the first time you ride your bike...
I know that I saw a video about it someplace, but FMF has it in stock if you want to order it...
http://www.fmfracing.com/Mode/Category/47/ (http://www.fmfracing.com/Mode/Category/47/)
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Yeah I just can't believe house insulation works. On the two stroke sections of thumpertalk seems a lot of guys use it. But I sure don't want to be repacking every time I ride and I don't want to waste the time experimenting if it doesn't work, lol.
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.House insulation will work it is the same makeup but not as dense as the pre packaged kit from fmf.If you choose this get the narrow roll that is put down on top of a foundation wall. It gose between the concret and the stud wall before they stand it up to seal air leaks. You will need to make a few rows of it and use some tape to hlod it while you insert the pipe.( its a real hassel)
The most important part of repaking is that you clean the holes in the pipe. if they are plugged up the noise cannot get to the insulation. so it will be as loud as it was before you started.
Forgive me MR.Nicholas but the insulation is trapped inside the canister between the pipe and the housing chances are it won"t blow out
Don't over pak,don't under pak..............BUY THE FMF PRE PACKAGED KIT 2-STROKES RULE
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I wanted to do it today is why I researched the house stuff when my local shop was sold out. But I think I will just wait until Thursday and try a couple different shops for two stroke packing and be done with it.
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I've used pink insulation for decades without a problem. I'm careful to clean the inner perforated tube each time and I've found the house stuff to actually be quieter then the moto specific silencer material. Even back in the old days during an almost 500 mile two day qualifier - never an issue.
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SachsGS how often to do you repack using the house insulation? I am intrigued and just might try it and until I can get to the shop.
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You guys got to be kidding me!!!!! House insulation? are you all really that cheap?Spend the $20 and get the stuff thats made to use in your silencer.......Man i think i seen it all now :o
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It has nothing to do with being cheap. I read about doing a web search and I am inherently curious person. I like to know things. There are a lot more people using it than you realize RideRed. I think I may just wait until Thursday to get to a shop for the regular packing, but I find this interesting that the people that use it like it, and the people that never tried it bash it :) . I don't like repacking silencers, never have enjoyed it in 30 years of riding and working on my own bikes, so I am just going to wait.
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I've used house packing in the past, seemed to work just as well as purpose built stuff, although I would reccommend wearing thick gloves and some kind of forearm protection as the glass in it can do some real damage to your hands and arms.
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First of all im not bashing anything,its called an opinion and im sure there are millions of ppl using it but that doesnt mean i am.I could care less if the whole world started using it........whats next using cooking oil in your motor? :P
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........whats next using cooking oil in your motor?
Hmmm... :D
I don't plan to use it either, but I am still interested to hear about people's experience using it.
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Use the real deal.You can use pink stuff and many other materials if you want to experiment but there's a reason the price conscious manufacturers use what they do.The backyard solution is rarely the best option.
Still,why not give it a shot coop and apprise us of your results/findings comparing the two.I've also heard tell of people using disposable diapers as well-just to throw another option in there.
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The reason I mentioned not to use the pink fiberglass stuff, is because the weave on it is very loose. This is engineered into the product for it's intended purpose, to insulate a home. The properties of insulation are made to offer "space" .... the insulation must expand to do it's job.
While I'm sure if you did a real good job of keeping the stuff tight, it "could" work pretty well, although I think in this case the purpose built stuff would work better.
Although what about a place like this to get it from?
http://www.bgf.com/muffler_packing/default.asp (http://www.bgf.com/muffler_packing/default.asp)
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Sponsered by Huggies........... :P
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I think my bike is slightly under-packed at the moment...
(http://i62.photobucket.com/albums/h119/JETZcorp/IMG_0326.jpg)
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If cost was an issue I wouldn't have TMs and Maicos in the workshop. European bikes such as Gassers,TMs and Maicos typically have these huge "honking" silencers and I find they are both quieter and make smoother power with the pink stuff. Why would I compromise performance?
I change the packing material when it gets saturated with exhaust debris. The bike will get louder and power will be "raspier". I carefully clean the inner diffuser,wrap it with the sound deadening material and secure with a little masking tape. Slide into the outer silencer and you are off top the races.
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For a two-stroke, regular house insulation will work fine. I've used it for years, and I typically get 15-20 hours between re-packs before the insulation becaomes burned and hard. The dedicated packing material may last slightly longer due to longer strands and higher density, but it costs far more. I can repack my silencer half a dozen times or more with house insulation for what it costs to repack once with genuine packing fiberglass.
Don't use house insulation in a four-stroke. The higher exhaust temps will burn the packing out very quickly.
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Yep i've used house insulation in the past with no problems.
I use the moto specific stuff now purely for convenience.
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Whassup! I've just repacked my silencer with that so-called house insulation. Looks like the previous owner o'the ride used that , too... I was really bored of getting that stuff out with a screwdriver... In our country it ain't no pink, but sand-yellow or tan. So i took some new stuff, luckily i have a huge pack in my garage, and got it repacked... The result is unbelievable: the exhaust sound is JUST THE SAME! It was a waste of time. ... :(
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LOL. I wanted to find out for myself so I did repack my nephew's CR80 Expert silencer with the pink stuff. It actually softened the exhaust note at the silencer, now I realize how much sound is actually coming from the pipe itself. That must be some thin metal used on the OEM pipe.
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LOL. I wanted to find out for myself so I did repack my nephew's CR80 Expert silencer with the pink stuff. It actually softened the exhaust note at the silencer, now I realize how much sound is actually coming from the pipe itself. That must be some thin metal used on the OEM pipe.
OEM pipes are made from 20 guage steel. And yes, they are a major source of noise. That's why the KDX came with a double-walled boat anchor...errr...I mean pipe.
The FMF Gnarly is 18 guage.
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That's why the KDX came with a double-walled boat anchor...errr...I mean pipe.
Indeed it was.Moreover,it hardly looked like a conventional expansion chamber unless you consider flat the norm.Still,tough as nails and worked well once you trashed the stock muffler.I wish I could get something like that for the YZ.I'd be more than willing to pay the weight penalty to get some durability.
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Both work just fine. I have used the "pink-stuff" and did not have any issues. Matter of fact, it is cheaper, more accessible,....trouble finding a reason not to use it. Just like pre-mix oil.......whatever floats your boat.
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We used to pack them with fine steel wool when I was a kid. Not sure if the bikes today would
be ok with it , but it's an option. I need to do mine and the dealer packing is what I will use.