Tachometer cable length

[Sable]

How would one go about shortening it? Mine seems to have had an extension fitted at some point for unknown reasons. It's now too long to be routed under the petrol tank and instead hangs out the side. Advice is greatly appreciated.

[pete376403]

Mechanical tach (ie cable like a speedo cable)? Original may have been replaced with one from a different bike.

[Sable]

Yep, it's a mechanical one.