making a colortune

[petrolhead]

Since i am trying to cut down on special tool costs (i just want to many)
I found a DIY tutorial for the colortune on flyingbanana.
It is good but the chipping away the porcelain is blunting my chissels in no time.
And it?s difficult, easy to damage the metal etc.
I found an easier way and decided to share it here.
Just cut away a small ring from the metal holder just under the porcelain with a angle grinder or dremel.
You can lift the porcelain straight out.

 

[Guest]

After you remove the porcelain, what do you install as a heat-resistant, electrically-insulated viewing window?

 

[Rich82GS750TZ]

??? any link to the flyingbanana tutorial?

 

[petrolhead]

Epoxy would be the easiest.
Below is the link;
https://www.theflyingbanana.com/tfbtechtips.htm

 

[petrolhead]

a nail for a pin welded to a 4mm. thread and taped to the top.
At the bottom end i have a small piece of tape (folded inside out) to stick the nail to the electrode to keep it centered.
After that i keep the plug upside down, stick it to a stand with tape and fill it with a seringe with epoxy.

 

[petrolhead]

With a flashlight it is clear but i will test it tomorrow cause it seems not cured yet.

 

[chuck hahn]

I did that tutorial long ago and it was no where as see through as the real deal. just my 2 cents

 

[petrolhead]

Well; the original one costs 117 dollar.
The nail costs me 7 cent and an old spark plug.
It?s worth a risk to me.

 

[Grimly]

Well; the original one costs 117 dollar.
The nail costs me 7 cent and an old spark plug.
It?s worth a risk to me.

Just don't stand with your eye directly in line with it.

 

[petrolhead]

Good advice !
I am wearing glasses so that is a bit of protection.
Chuck is right; it is hard to see specially in the sunlight.
But under a blanket with a fan for the heat it works.
And because i won?t use it often it saves me some cash for every day tools.

 

[Forden]

any chance you might post a video? Curious how well it worked out.
cheers

 

[petrolhead]

https://www.youtube.com/watch?v=4T1FzNnIXe0
it is evening here, so better visible.
I can?t seem to get the blue color.
Maybe i need a smaller set of pilots.

 

[Cipher]

It works well enough.
kudos.

Are these cv carbs? I've read colourtune is not as useful on them.
Also maybe the nails impedance is impacting the spark colour?
Is it up to Lucas electrics standard?


Nice video space manipulation. Makes me wish they'd shot Lawrence of Arabia vertically.

 

[petrolhead]

The carbs are VM slide carbs.
The nail is a common iron nail, i have not thought about impedance.

 

[Cipher]

The carbs are VM slide carbs.
The nail is a common iron nail, i have not thought about impedance.

https://www.bluesea.com/resources/108/Electrical_Conductivity_of_Materials
Ngk standard plugs are copper core. I imagine its a tiny strand but they would not spend the money without reason.

 

[petrolhead]

I have thought about brass/copper but was afraid it might get too hot in the head for a different metal.
They might use a mixture of metals and i know nothing about melting points.
So i thought iron was the safe way to go.
My carbs are way to rich so i first try to get them leaner and see if the flame turns blue.

 

[Forden]

Thanks for sharing the vid. Looks like it does the trick well enough, even if you have to make a second version with more conductive material. With the covid-price-gouging for the Gunson originals, I might have to make an attempt myself...