199A Silencer Packing?

[scot taco]

I have read that one of the things that they did to help keep the factory bikes in top tune was to keep the silencer properly packed.I don,t see any way to do this unless it was cut open.Is that what they did? I haven,t had mine off the bike yet,but I,m guessing they are talking about the end silencer/exhaust piece and I,m just curious how to repack it if thats possible or even necessary?

Edited January 20, 2013 by scot taco

[bondy]

hi scot i dont know to much about this but they do have to be cut open the silencer.and the middel part get repack all my bultacos have had it done. think bultaco uk can have it done for you it was £50 last time i ask. from what ive read in the passed it dose help. aslong as evrrything else is set up as it should be like carb timing points. sure the guys will addvice you. cheers bondy.

Edited January 20, 2013 by bondy

[pschrauber]

If the silencer is clogged it's worth the effort, performance and soundwise.

For the performance I would take a look inside the mid section from the rear there is a holetube installed with is attached to the manifold between the holetube and the corpus of the silencer should been a kind of mineral isulation material. Mostly the holes of the holetube are clogged. and had to be cleaned too.

The rear section of the exhaust has luckily only in the first third to half again a holetube and isulation mounted also this holetube has to be cleaned and the isulation has to be replaced.

For the isulation I would recommend exhaust isulation which comes in mats, due to the case that in the middle sections of the exhaust the hole tube has a free end and when you have filled the voids between the holetube and the corpus to light it can be blown out. In the other hand filling the void to thight will decrase the performance and silencer effects.

Here a picture of the opened rear section of the silencer:

Here a sketch of inner parts of the mid section:

For the exhaust insulation material, I only have a German dealer at hand, you should find this stuff in every other good dirt-bike dealer store:

http://www.mxladen.com/Auspuffdaemm-Matte

Wrap the insulation around the cleaned holetube, secure the mat with wire in the middle, then you can if necessary reshape the ends. Place it in one half of the exhaust,

fasten the hole tube to the manifold, (brazing or some welding points) then you can close the corpus again.

[scot taco]

Thanks Bondy,it,s good to know that I can have it done if need be.

Thanks pschauber for the pics and details on how to do it.I will probably try and do it myself to save $,especialy knowing that I could send it out if I screw it up.I do a lot of welding at work and I have a mig welder at home so I think that I should be able to do it.The tricky parts would maybe be not getting things too hot when welding and getting the packing in correctly.

[woody]

If you search the Bultaco forum using the word 'packing' you'll find some previous topics on packing the exhaust with more useful info.

[scot taco]

Thanks Woody,I did find more helpful article.

[colinf]

Hi Scot, it's worth doing and as you can weld you'll have no problem.I did it on my nephews Gas Gas and it transformed it.I've done it on my 191 but as it's not finished i can't comment on the improvement yet.Hopefully i've attached pitures so you can see whats inside ( please note on middle box a previous owner cut it across it's length! this will be tidied up later) I would suggest that you remove and replace the perforated tubes as they are very hard to clean properly and you can buy perforated sheet cheaply and make your own.

[scot taco]

Thanks Colin for the great pics.I had to disassemble the bike today so I could cut the swingarm bolt out.When I removed the end silencer I noticed something loose inside rattling around.I wasn,t sure if I was going to cut it apart,but now I am and your pictures are a big help.I would assume,from what I,ve read,that it would be the perforated tube thats come loose,but it sounds like it,s in the end like maybe a baffle plate.

Where did you buy the new perforated sheet? I,ve never seen that before.

[colinf]

Hi Scot, I'm lucky enough to have a long established hardware shop nearby that has a metal warehouse.I think it was only about £6 or £7 pounds for the piece in the middle box and not much more for a bit big enough for a couple of attempts at the one in the rear box, they were both under £10 each.I would suggest you use a thin 1mm cutting disc and try not to cut too deeply around the baffles, i had to fill the places where i'd nicked them with a spot of weld.As you're not exactly local have a look on-line,someone must sell it over there.

[b40rt]

ebay sells perforated steel sheet.

[colinf]

If it helps it was on receipt as mild steel perforated sheet 2x3x1mm and it was £7.72 for a piece 15cmx25cm.

[woody]

You can buy perforated tubes, no need to make them

[scot taco]

Thanks for all the info gents! This site and all of you are a huge help.