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TR6 1973 TR6 ZS carb mixture

sundown

Jedi Hopeful
Offline
I am trying to fine tune the mixtures on the 175CD carbs by the spark plug method do I pull the #1 and #4 plug and check the color or do I need to pull all the plugs?
 
You can look at just #1 & #4 if you want.

Worth noting that unleaded fuel produces different colors than the old leaded did. Lead oxide is a very strong white pigment (which is why they used to use lead in paint) so it was part of the color seen on plugs (and inside tail pipes). And some modern fuels use other additives that produce other colors. I don't know if anyone in the US still uses MMT for example, but it leaves a funny pink-orange colored deposit on the plugs.
 
One and six because of the configuration of the intake manifold would be my choice, but if this is the first time, I'd pull them all, but only after I had driven at least 250 miles, enough for whatever color has time to develop.
By pulling all you might see some differences among the plugs. If uniform amongst the set of 3 then you can feel safe in selecting one the next time....and there will be a next time, to represent the other 2.
 
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