Eratic rev counter...

[rcorbett]

Firstly, I will get around to buying Steve Heaths book one of these days... Secondly, the revcounter in my Chimp is going a bit doolally. Fine under acceleration but cruising & on run off starting to go all over the place. Any ideas how to fix the prob ? Got a horrible feeling it involves a new dial & taking the dash off

[vroom]

Had similar problem on my Chim - rev counter would jump all over the place. Cured by replacing the spark plug leads. Poor lead suppression (voltage spikes) was causing havoc with the electronics in the tacho.