[Prowbar]

Using the exhaust gas meter we adjusted the emissions today. Before it was almost 6% CO (carbon monoxide) at idle which is extremely high. However, with propane, you don't really notice the excessive hydrocarbon smell (at least outside). Readjusted the idle and checked the emissions at 2500 rpm which was fine.

We set a goal for about 1% CO at idle, which is still a little rich for propane but makes cold starts easier. With the dual exhaust on the left-right values differ a bit but nothing to worry about. The mixer is really sensitive to changes and when we got close we left it as is.

Overall very happy with the other values such as the unburned HC which are really low for an old engine like this. I think this is due to the HEI + PCV conversion. Out of curiosity, I might revert to the stock PCV and spark plug gap and then recheck. Should have done this when the points were still installed but oh well. I have a feeling the stock PCV system will produce more unburned HC's.