My Rover Metro 1.1 carb model just had an MOT and the CO is high! HC level is 351ppm, well below the pass rate of 1200, but the CO is 7.69% and the limit is 3.5%. The car has only done 31k and I replaced the diaphragm on the KIF38 carb as it was perished causing a very high fume output from the exhaust. By Diaphragm I mean the one in the side-mounted enclosure that is termed a "full load enrichment device" held in place by some torx bolts.

....any ideas? Ideally I'd like some idea of how to adjust the torx air bypass screw in the FLE device and the mixture screw that alters the jet height.

I think you should get at specialist garage to adjust the mixture for you. shouldn't take them more than 5 minutes.

What do you reckon to these instructions - though they do not seem to include the FLE device air bypass screw?...

http://sucarb.co.uk/technical-hif-type- ... ing-single

Those instructions are good although a bit difficult to understand and can also be a bit difficult to perform on the car. That point where the curve breaks is not nessecarily easy to spot.

An other thing with the instructions is that they only gives a correct setting if the carb is in good shape. And i dont know that other thing your carb has as i only know hif carbs and have never touched a kif as i believe yours is called.

Also you can set up the carb correctly with this procedure but you wont know where the co is at unless you measure it