Time for weber tuning

[Enrique Claure <spanlab@ceibo.entelnet.bo>]

Hi list, I have to tune my weber carburator. One option I have is take it 
to a pro mechanic that has these fancy instruments and gas detectors. It 
cost 50U$ per tune up and he take about an hour. The other option is to get 
that blue flame color spark plug that gives you a visual idea of the 
air/fuel ratio. This kit costs 40U$ and I get to keep it. Any ideas? Enrique