Skywing (like G10 Charade)

By chance I got a look at the analyser screen when I was in for my half year vehicle inspection here in Taiwan. 4.7 % CO, 7.2% CO2, IIRC. Didn't see the HC but presumably high (They don't give you a printout, probably the thinking is "no numbers, no pack drill" ).

The posted limits for a 1990 car (mines 1986 which wasn't posted) are 4.5% and >9%, so that should probably have been a fail, but the private centres tend to cut you some slack for the repeat bizniz. They also don't want the additional hassle of communicating a fail to a foreigner. Dumbness brings dividends.

Their meters are allegedly "tuned" to read low anyway, so it may be running dirtier than that.

The plugs look OK though.

Couldn't remember the UK MOT emission limits, never having failed a UK test, so I checked them online. (Havn't found the Taiwan ones, but I'd expect them to be similar but perhaps introduced later. It appears from a quick look that, in most US states, a car of this age would be exempt)

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/194133/Emissions_17th_Edition.pdf

The CO limit shifted from 4.5% to 3.9% during 1986, but there is no mention of a minimum CO2 value. Having one would perhaps prevent faking through a test by bleeding some air into the exhaust, which I've heard of, but never tried. It'd be quite hard to hide the plumbing in a UK MOT inspection, but easy in a Taiwanese one.

I suppose I'd better try and tune it leaner, a bit daunting since the last time I tried to understand all the ancilliary plumbing hanging off the carb, I got a headache, and my choke stopped working.

Would a vacuum guage help with tuning? (assuming I could find one here, by no means certain).