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Can I use residential type fiberglass insulation to repack my silencer?

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We could all buy the residential fiber glass insulation for a LOT cheaper than the stuff at the bike shop, so can we use it to repack or not? Why and why not? What makes it special?

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You can do anything you want, but I wouldn't use home insulation. It doesn't dampen sound as well, will actually absorb a lot of water, and won't last nearly as long as the proper packing material.

Just spend a few bucks and get the correct material and make sure you get for either a 2-stroke or 4-stroke muffler as needed.

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I agree with used yz. $8 for three packings is already cheap. I dont know the scientific answer youre looking for, but i know home insulation seems much thinner than the strands you get for dirtbikes, so i feel it will pack down faster.

This is such a preference issue that i would just do it with the home stuff you must already have and see how it goes. Then repack with the fmf stuff for instance. Youll have your answer either way.

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I thought it cost much more. How much is it?

$7.99 for a bag that will do at least 2 repacks. 3 or 4 if its a shorty.

If you get the 'pillow' type replacement packing it could be as much as $20. But the bag of strands from fmf work just fine.

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It's the only thing I've ever used.

So you do use the residential stuff. Any problems with it?

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$7.99 for a bag that will do at least 2 repacks. 3 or 4 if its a shorty.

If you get the 'pillow' type replacement packing it could be as much as $20. But the bag of strands from fmf work just fine.

I agree, the real packing is a good deal. The home insulation seems to be lighter weight and less dense from my observations. I don't think it will last as long as the proper 2 stroke packing.

I've been using both FMF and Moose brand packing in my YZs. Both last a long time.

If you want your packing to last a long time, kick down the 4 bucks for a muffler plug. It will keep the water out of your exhaust when you wash the bike. Make sure you get a proper 2 stroke plug... the four stroke ones are too big. The best one I have is rubber, it's made by Moose.

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$7.99 for a bag that will do at least 2 repacks. 3 or 4 if its a shorty.

If you get the 'pillow' type replacement packing it could be as much as $20. But the bag of strands from fmf work just fine.

OK thanks. I will check it out at the local bike shop. Are you supposed to pack it real tight or just so it fits? Any advice?

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Wow, Really? $7 yes SEVEN dollars the Fly Racing packing cost me...All the other brands are @ under $10 too...Why even risk it? I would be worried more about absorption than anything else.

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Well because a while back I thought I saw a package of it labed like $80 or so. I figured that it was a little steep. I guess perhaps I misread the package or it was mislabled. Thanks for the replies.

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So you do use the residential stuff. Any problems with it?

No, I have never had any problems with regular old pink fiberglass insulation.

Even if the newer packings last longer, it only takes 15 minutes to repack a silencer, and for $20.00 you can buy a lifetime supply of packing at Home Depot.

As stated above, what do you have to lose by giving it a try back-to-back with the stuff currently sold as "motorcycle specific". Make up your own mind.

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I think I paid $9 last month for a package of FMF packing from the local shop for my sister's Buell (I'm the winter care-taker / maintanance guy).

The pink home insulation stuff will work, but not as well. As said, the strands are thinner and shorter. Good for R-value, not intented for longevity in a silencer. Blows out much quicker in my experience. Not to say you can't use it or that I wouldn't (have many times), but I use the "correct" stuff 90% of the time.

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Well because a while back I thought I saw a package of it labed like $80 or so. I figured that it was a little steep. I guess perhaps I misread the package or it was mislabled. Thanks for the replies.

Haha gese! Sounds like a price the guys on ebay try to sell stuff. Side note, in case you didnt notice, a lot of ebay stuff is marked as high as brand new oem stuff but its used. Not always but just sayin.

Hell for $80 id buy a new silencer every 30 hours!

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You sure can. It does absorb water and oil more, I probably go 20hrs on a packing, then it will start to get a funky smell. I have enough leftovers from home projects that I see no reason not to use it.

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I have enough leftovers from home projects that I see no reason not to use it.
Same here. I still have quite a bit leftover from adding insulation to my attic, using it to re-pack my silencer every twenty hours or so sure beats throwing it away. :smirk:

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My question is do you leave the paper backing on or peel the fiberglass off?

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My question is do you leave the paper backing on or peel the fiberglass off?

I've never bought the type with the paper on it, but you would have to remove the paper in order to pack it into the muffler.

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I use the type with the paper on it, just remove the paper and pack as normal. I think I'll try the FMF specific packing, but got a lot of this stuff to use up.

...

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