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125 Beta Evo - Exhaust Packing Question

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Hey guys,

Quick question about the exhaust packing in my 2010 Beta EVO 125 2T. I've noticed that my bike compared to other bikes of similar age is a lot louder. Most other bikes I can not only hear the exhaust but also a bit of engine noise too, there exhaust almost seems to "putt" where mine seems to "pang". Mine is a more of a harsh sound and it sounds like the packing is not absorbing much of the sound at all, I popped the end cap off the bike to discover a bunch of grime and goop inside the lower silence itself and similar but a lot less inside the end cap. The goop in the exhaust is blocking all of the holes in the metal baffle. I've read that if you get the exhaust hot enough some of this can burn off, but this looks really goopy, what's the best option in my case? Go for a hard ride? New silencer time? Throw some petrol down it?

Photos inside the exhaust system (scroll down for all the photos, click to zoom): http://imgur.com/a/eyRKH

Edit: I'm running 98 octane with Motul 800 2T oil, 72:1 (same as the previous owner)

Thanks :hyper:

Edited by jml

No matter how hard you ride it a trials bike is eventually going to need the perforated tube cleaned and the packing replaced. It's an easy job and, now you've got this far, obvious how it's done. Just don't put the new packing in too tightly. I don't see blocked holes in the photos, it all looks very clean.

Edited by 2stroke4stroke

The center section can be burned off as the only way to open it is to cut then re weld (if its the same as a Rev3). I used a blow lamp hang it upright when it is hot enough it will burn the oil off on its own but do it outside and preferably without anybody around.

Mine burned for over an hour I just had to apply a little more heat from time to time. It weighs about half what it did.

I also did the front pipe but wasn't much in that but the carbon fell off easily after getting it hot.

Edited by richfr

Oven cleaner and pressure wash works pretty well.

Centre section does have to be cut apart. Lack of centre section packing is often why and older bike never quite runs as "softly" as a new one.

Do exactly as richfr suggests, I've done it many times on a 125 Evo. I also use the blowtorch on the front pipe, as there's a large chamber which gets clogged up. Usually burns for ages. The front pipe will turn a light golden colour, but you can use steel wool to bring it back to silver. You'll notice a huge difference in the noise and power output :)

  • Author

You'll notice a huge difference in the noise and power output :)

What type of difference did you notice in the noise from the exhaust after doing this?

Your bike will sound quite loud and raspy at the moment because the silencer internals are clogged and not absorbing the exhaust pulses. When you've cleaned the whole system out and re-packed the tail pipe, it'll sound much quieter.

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