Triumph Repair: 73 Spit running too lean and high CO output, co hc, rich mixture

Question
Howard- My spitfire just recently failed emissions in Colorado and i was wondering the best way to fix my problem.  They indicated that it ran too lean and the CO output was too high.  How do I make the appropriate adjustments?
Thanks, Ross

Answer
Hi Ross,
You have it backwards. CO is mixture and when the readings are too high on a CO/HC test then it is too rich not too lean.

When reading the CO and HC you can count on high CO is a rich mixture and high HC is either an ignition problem or an engine problem. However excessively high CO will cause HC to go up and extremely low CO will also cause HC to go up because HC is Hydrocarbons which is unburned fuel.

If you just failed because of high CO you just need to lean the mixture. If you are not familiar with the procedure let me know what carburetors you have and I will give you the procedure.
Howard