I’m repacking the muffler on my Beta Rev 3, and I need to replace two O rings. This is my first time doing this, so I’m not sure if I need specialised, heat resistant O rings or can I use the common ones from the local home centre? I asked at the local home centre but they didn’t know. 
 

Thanks in advance. 

 It does not matter, but I always used a dab of high temp silicon with them.

I would try normal Nitrile O-rings. If problem I would use Viton O-rings.

https://www.nes-ips.com/viton-vs-nitrile-o-rings/

Carl

4 hours ago, lineaway said:

 It does not matter, but I always used a dab of high temp silicon with them.

The ones in the local home centre have a temp limit of 80 degrees. Plus they don’t have the size I need. Looks like I’m going to have to source the Beta ones and splash out. Thanks for your advice. 

Yes , you need special orange O-rings.... high temp...., i use special silicon for cylinder side..!!

Having just gone through this, I ended up buying a length of 2.5mm viton oring cord and then just made my own orings, using a dab of superglue to bring the ends together.  It works great, its cost effective and you'll get to use your math skills for calculating the circumference if you haven't got one of the original o rings to determine the length of cord you require.

These are the size and type as listed in parts list from Beta if it's the front 2 O Rings https://www.polymax.co.uk/o-ring-52-07mm-id-x-2-62mm-cs-fkm-viton-brown-75-sha

I can't recall if I ever had a problem with those rings when I repacked the silencer, I certainly did not buy fancy ones if I did.  I probably used silicon too.  I used to use ordinary diy silicon to seal the exhaust port on my IT 250 and it had enough temperature resistance for that so a tailpipe should be ok.

Thanks for the advice everyone. I’m in Japan, and my Japanese reading ability is not the best, so navigating the websites over here is not easy. That said, I found a trials supplies website that not only sells the o-rings I need, but it also has muffler padding cartridges for the Beta Rev 3, which I was surprised to find. Thanks  again.