Had a loud rattle from the back of the bike (Alpina 213), so pulled off the rear silence and give it a shake - something heavy adrift inside. I thought I’ve nothing to lose so took the disc cutter to it:

Having fished it out it appears to be the same size as the lower tailpipe, but where does it belong?

 

Edited April 12, 20215 yr by mick annick

Having given it a quick clean there was still something a bit loose inside, so I opened up the other side and found the packing was shot (already removed when I took the photo), so will replace this with stainless wire wool.

 

Edited April 12, 20215 yr by mick annick

This is how it comes from the factori, the Hemblosh resonator is fine tuned to different frecuencies, best to leave it as it was made for maximum engine smoothness, some people "destroy" the internals for stronger response, the wrong way in my opinion as I tested both systems in my bike/s and I have to admit that Bultaco new how to do it. 

Just my 2 cents...