re post of spark plug color ?

[120]

2nd try,
I had to remove a couple of plugs to remove my engine and I noticed that they were almost orange on one side and a little darker on the other. Last time I changed them they were the perfect dry tan grey. Since then I have increased the mains and air correctors. (looking for a little more umph)And if it makes a difference I do have an after marker ign. Less than 1000 miles on them.
So, what does "orange " plugs mean?

Bruce

[papajam]

Can't say that I've seen orange plugs before so can't comment...yet. But a few questions;

What were the main and airjet sizes before the change and what are they now?

Are the orange sparkplugs the same brand and heatrange as the tan ones?

Was the aftermarket ignition there with both sets of plugs?

In my experience, I've found that rejetting, for the sake of rejetting, has little, if any effect on performance provided that the mixture was OK to begin with.

[120]

hi papajam,
The ign was the same, as were the plugs. Guess that means its up to the rejetting. Could be the winter formula gas?
Right now I can't remember the exact jetting. Around 115 to 120 and like jump in airs. What you say makes sense, I had planed to increase the aux venturies but they were already the size I had bought to replace them with. 30 for a giulietta 1300, how was I to know? Works pretty well.

Bruce

[papajam]

Wouldn't blame the jetting just yet. Did a little reading and found this in a sparkplug catalog;

<Glazing appears as a yellowish, varnish-like color. This condition indicates that spark plug temperatures have risen suddenly during a hard, fast acceleration period. As a result, normal combustion deposits do not have an opportunity to "fluff-off" as they normally do. Instead, they melt to form a conductive coating and misfire will occur.>

After reading this, I now vaguely remember an article in an automotive journal (decades ago) that refered to the effects on new plugs when an engine was floored repeatedly after a fresh tuneup (something the car owner, like me, likes to do). The recommondation was to go easy for the first few hundred miles (yeah, right!) to 'break in' the plugs. If the acticle did have merit, it never carried any weight with me.
So maybe your orange plugs are in the catch-all category 'they all do that'.

[Mr. C.]

Hi 120,

I quess we need to define colors here. I have seen orange plugs caused by refomulated gas in the Philadelphia area. Plugs looked fine but where they used to be grey or almost white, they were orange. Here in the Shenandoah Valley I don't see that. Same car same driver "same Mobil Gasoline. Don't know if you have orange or glazed. Gees this sounds like dunkin donuts.

Anyway if it is orange from the fuel it is nothing to worry about. We had a young woman next door in PA who drove a 73 Spider and worked as an engineer at Sun Oil. She took the plugs to work and reported no problem.
MrC

[120]

thanks Mr. C,
it may well be the "winter" gas we have in the Seattle area.
We had a track event about a month ago and the gas was in the tank before that. As you know winter here in Seattle ends after June.

Bruce