The Tach on my 82 has had a slight pulse since I got it. There is no miss in the cylinders and the rev limit wire has been disconnected. The needle will bounce about 250 -500 rpm at regular intervals (about every 2 seconds), it doesn't matter what the actual rpm is. There's about 15,500 miles on the bike. Any suggestions ?
LD
The only thing i can think of to try would be to clean all the contacys in the back of the tach, the connector & at the tci. failing that, you can replace it. someone here will have one.
probably one of the electronics experts here like Walt or Extent could diagnose them more thouroghly.
The tach gets its signal from the low voltage inputs to one of the spark coils. Clean all your low voltage spark coil connections. Also clean the ground wire that uses the spark coil mounts for what I think is the primary ground on the frame. Cheers.