Carb or Ignition issue?

[stevieturbo]

At 12.2:1 idle I'd be surprised if it passes any legit MOT !

On paper...in theory, 12.2:1 suggests around 6% CO.

Although as lambda sensors do no actually measure mixtures and are affected by other things....AFR from a wideband converted on a table cannot be relied upon as accurate vs a gas analyser CO reading

[sidecar]

At 12.2:1 idle I'd be surprised if it passes any legit MOT !

On paper...in theory, 12.2:1 suggests around 6% CO.

Although as lambda sensors do no actually measure mixtures and are affected by other things....AFR from a wideband converted on a table cannot be relied upon as accurate vs a gas analyser CO reading

It's a kit car, the law on their emssions seems to varry depending on who you talk to. The log books states 3.5% from memory, maybe even 5%. I seem to recall that it was tested during one MOT and it passed. Having said that I can't remember what the pilot screws were to but I've never reset them for an MOT.

[stevieturbo]

At 12.2:1 idle I'd be surprised if it passes any legit MOT !

On paper...in theory, 12.2:1 suggests around 6% CO.

Although as lambda sensors do no actually measure mixtures and are affected by other things....AFR from a wideband converted on a table cannot be relied upon as accurate vs a gas analyser CO reading

It's a kit car, the law on their emssions seems to varry depending on who you talk to. The log books states 3.5% from memory, maybe even 5%. I seem to recall that it was tested during one MOT and it passed. Having said that I can't remember what the pilot screws were to but I've never reset them for an MOT.

Goes by age of vehicle or age of engine...whichever you can prove as oldest. So unless it's something modern it will either be 4.5% or 3.5% max.
It'd need to be pre 1973 or so for just a visible smoke test.