Hi Folks,

I'm building a motorcycle up as a project at the moment, it uses a honda c90 lump, the issue is the only exhaust that will fit the frame and has an exhaust flange that fits the stud pattern is a bit small and weedy.

This isn't a massive problem, as power is not a concern, its just for my little lad to learn on. The problem arrises when I try to get the smaller OD of the exhaust to sit in the larger OD exhaust port, as it isn't a tight fit (approx 5mm all round) - whilst the flange will hold it in place fine, I am concerned I will not seal the exhaust very well.

So I'm thinking a large copper crushable washer sat in the exhuaust port, taking out the difference in the OD of port (note the ID of the port/exhaust is roughly the same, so that isn't a problem) and any slight implerfections on the two faces mating (I have had to rebend the exhaust a bit to get it to fit).

Are there any other options? Do people agree that the copper washer is a good starting point?

Cheers

o-ring of suitable temp rating?? just a thought