Speedometer Trouble

You cant kink the cable or shieve. Cant turn a sharp 90 degree corner. The cable cany ne so long that it applys pressure to the instrument.
So make sure its routed a slow curve under the driver seat. Make sure its routed to the instrument correctly under the dash. Leave the collecter nut loosened and try it again. If all the cable bugs are squished yet the needle still bounces ...the insturment is the fault.