The Saito 180 really does have problems holding onto mufflers. I know of people with the same problem which never got resolved, even with Saito's help (of what help they really are). Our field is littered with lost pipes and mufflers, but none of them mine!

I recommend forget using vibe dampening with the Saito 180 and just use solid aluminum rails. The idea is to transfer the vibes to the frame, forcing the engine to be more solid, let the frame deal with it to protect a poorly designed exhaust system. I share your pain with Saito's engineering feats and lack of support! In my experience with them they refused to stand behind their engines. (just my experience with Saito and other issues then muffler). Yes I have Saitos and I like them in spite of their issues and poor support.

I think the Venus II will have no problem without vib dampening, and i am also building a GP Ultimate and do not plan to put any dampening there either. On the ultimate reinforce firewall with dowels and consider fiber glassing the joints. I am.