strange idle!?!?
 

I was experiencing a strange idle.....it had no particular pattern, sometimes up sometimes down!? All the plugs points etc. were new. I removed the carbs and noticed that the butterflies were not closing at the same time. Upon MUCH closer inspection I noticed that there is supposed to be a small plastic/rubber spacer on the linkage between the throats that makes them work in unison. It was missing on one side and partially visible on the other. I made replacements out of rubber and now the idle is normal and better still, consistent!
I hope this helps anyone who might be having a similar problem. Its a VERY easy fix for a VERY perplexing problem.