Originally Posted by
tabetha
The reason it only just scraped through is because it is running so lean, leading to a lot of unburnt fuel in the exhaust, this is your PPM, it will be much higher if running too lean, as a rough guess I'd expect from yours nearer 2 % CO, and 100-300 ppm.
tabetha
So what would it need doing to be able to get to your estimates?