In the process of sort out my fraying exhaust valve cable. I noticed that the spring on the top my exhaust valve is missing (08 XB12XT). There is one on my spare silencer (from an 06 XB12X), but it doesn't appear to do anything? The return spring for the valve is inside the exhaust, and opening the exhaust valve doesn't put any extra tension on the spring on top. So other than keep the tension on the valve shaft, it doesn't appear to do anything?

This isn't my silencer, but you can see the spring I'm talking about

The spring appears to be to retain the shaft? It seems to be a pretty elaborate way to do it, an R clip would have done the job.

S0097.1AAA SPRING, SHAFT RETENTION MUFFLE