Cold Weather Effect on Mixture
Turbo Mini Forums

I think I am just confirming what I already know here but Andy and I went out in the van last night.

I noticed that the van was running significantly leaner than usual.
It usually holds an AFR of around 11.8:1 at full tilt, however last night it was around 13.4:1 and felt to be a touch down on power.

As a little test I decided to pull the choke out. AFR's came down to around 12.5:1 with what felt like more power than its ever had!

I take it that the "effing" cold, damp weather equates to denser air and a colder charge necessitating more fuel?

If something is worth doing, it's worth doing half of.

The joy of that fantastic device, the carburettor.

correct john 12.5:1 is where all the fun is ................correct mixture for best power

Its the damp part that has affected you a little if the air was drier you would have made a little more power.
My engines have always run better on cool summer nights than autumn nights.

If I remember correctly when you add water to the charge you have to add more fuel to help turn the water to steam.

So as you correctly observed pulling the choke out saw a gain in performance as the extra fuel provided the energy to turn the extra water to steam.

Own the day