Muffler packing to reduce noise?

[djudju]

Hi there
My bike need to go through compliance following a crash and a write-off by insurer. Only issue is with the exhaust being too loud. The guy said that they will be happy if I packed the muffler.
The muffler is already half filled with the fibreglass thingy so I wonder how high I can go? Is that OK if I go past the little holes? I have added couple of photos.
I have looked only online but most of the info I find is to wrap mat around silencer when silencer can be removed. Mine is not like that.
Thanks for your help.

[hayd3n]

last time i wrapped my zorst i had to drill out the rivets and wrap outside the inner tube , have you got some pics of the exhaust side on?

[nzspokes]

last time i wrapped my zorst i had to drill out the rivets and wrap outside the inner tube , have you got some pics of the exhaust side on?

Well yes. That looks to have it stuffed down the center.

Huston we have a problem.

[bogan]

Need more info on the muffler, not sure what type it would be (some reduce noise by passing exhaust gasses through a number of tuned length chambers, while other use packing material to soak up sound energy while leaving the gas's flow largely unimpedded, other use a combination of the two). Reckon whatever happen you'll have to get into it to fix it anyway.

[djudju]

Thanks for your help.
After checking a bit more, I was able to open it up :-)
This is the muffler:
http://www.shop.modernmotorcyclecompany.com.au/products/muffler-reverse-cone-megaphone-shorty-black
I packed it but didn't notice much difference. Maybe slight less noisy :s
Hope the guys at compliance will be happy with that.

[imdying]

Get a penny washer and have an exhaust shop tack it over the outlet. After your compliance, grab it with some vice grips and wiggle it till it breaks away.

[GrayWolf]

Hi there
My bike need to go through compliance following a crash and a write-off by insurer. Only issue is with the exhaust being too loud. The guy said that they will be happy if I packed the muffler.
The muffler is already half filled with the fibreglass thingy so I wonder how high I can go? Is that OK if I go past the little holes? I have added couple of photos.
I have looked only online but most of the info I find is to wrap mat around silencer when silencer can be removed. Mine is not like that.
Thanks for your help.

If this is the same as the old 'reverse cone' megaphones we used on old Brit iron... (they were basically a straight through, a perforated tube down the centre) sometimes with a 'plate' with holes or multiple small dia' tubes at the end.
My current mufflers have that same construction.... similar shaping (design) with 42mm perforated tube running the length of the muffler with (good quality) packing between it and the muffler wall, the packing is TIGHTLY packed in that space, (often the wrapped around the baffle tube method is cost cutting rather than for gas flow) and fills the space between completely, but there is no 'baffle plate', or gas restriction in the 42mm tubing. to fill my mufflers 1.5 bags of packing were used, costing over $100, which if you worked out manufacturing cost to retail sale of shop purchased ones made like that???? Possibly you may need some back pressure (baffle plate?) but if the basic design is a straight through... fill 'er up with packing!!!

Also after about 18 months-2 yrs (I was informed) the packing will likely need redoing.

[AllanB]

If it is like that black muffler the reverse cone comes off when you undo the screws (may be rivets) the insert will usually be held in by a couple screws too - remove and repack around the core - reinsert - it should be tight to get it back in - more packing is good.

That's presuming it is similar to the one you posted.

Also watch this - principle is the same. The packing those cheaper aftermarket pipes come with are crap - I am pretty sure they are just lots of old mens belly button fluff

https://www.youtube.com/watch?v=RNxKO18I-3I

[F5 Dave]

Unlikely that shoddy cheap piece of shit will ever be less than offensive. Best to suck it up and buy a real muffler.