Gunson Colortune

[stevee.b]

Hi Folks
Looking at the Gunson Colortune and I can see from other posts that we need the 14mm plug size but I’ve not found any mention of whether we also need the long reach 14mm adaptor as well?
Thanks in advance

[Tdafforn]

Not sure about the plug extension. But just be aware that the flame colour chart for color tune doesn't really work that well for modern fuel. I use an afr sensor and it shows the blue flame in a colour tune is too weak. You need a yellower flame.
tim

[MandM]

I just use the std 14mm Plug colour tune

[richardthestag]

personally I would lob it

Using the ROM method to get the carbs tuned is quite good and you only need to get to 4.5% CO for 1975 onwards iirc. Which to be frank is dead easy for a good set of carbs

[mole42]

I'm quite interested to install a couple of lambda sensors just to see what the afr is actually doing and comparing left side to right side. Has anyone discovered the best place on the manifolds to drill the hole?

[jbuckl]

I'm quite interested to install a couple of lambda sensors just to see what the afr is actually doing and comparing left side to right side. Has anyone discovered the best place on the manifolds to drill the hole?

Downpipes. 4-5” from flanges.

[trunt]

I decided that one side was enough, as both carbs feed each side so you are seeing them whichever side. I chose the left as it seemed easiest. With wide bands that are heated it’s not essential to get them near the engine so mine is positioned just in front of the bulkhead line. It’s important to mount them on the top of a horizontal pipe, to avoid water pooling.

Terry