Autolite spark plug number
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ModelTWoods
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Autolite spark plug number
What is the Autolite spark plug number for 1/2" thread base plugs? I have seen three numbers: F11 , #25 , and 3095.
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bobt
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Re: Autolite spark plug number
O'Reiley auto parts under $5. Autolite 3095 I ran them for the last eight years. bobt
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big2bird
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Re: Autolite spark plug number
Sparkplugs.com
3095 $5.80
425x. $31.95
3095 $5.80
425x. $31.95
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ModelTWoods
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Re: Autolite spark plug number
Thanks to both of you. I knew Champions had gone out of sight. I still have some NOS Champion A-25's. I wonder how they compare to Autolites?
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DanTreace
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Re: Autolite spark plug number
Just one potential problem with Champion 25 is the electrode is just threaded into the ceramic and potted to the porcelain.
If you use more than finger tight on the thumb nut on the terminal, the potted electrode can be broken away inside and lead to hidden misfires.
Run the 25 in the Prus head and they work fine, normally gap at .025" as run on Ford magneto and good results.
If you use more than finger tight on the thumb nut on the terminal, the potted electrode can be broken away inside and lead to hidden misfires.
Run the 25 in the Prus head and they work fine, normally gap at .025" as run on Ford magneto and good results.
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford
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ModelTWoods
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Re: Autolite spark plug number
Dan, Would there be a difference between Champion A-25's made at different decades? Is the electrode threaded on all of them? My box of NOS Champion A-25's were made in the 1950's or 60's, at the latest, and I never noticed the electrode issue. The have A-25, not just 25 on the porcelain and have more ribbing on the porcelain, If I remember correctly, but its been years since I looked at them.
Last edited by ModelTWoods on Wed Jan 28, 2026 2:13 pm, edited 1 time in total.
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Mark Gregush
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Re: Autolite spark plug number
My experience with the 25's was the same as Dan's. Mine were from the 90's.
I know the voices aren't real but damn they have some good ideas! 
1925 Cut down pickup
1948 Ford F2 pickup
1925 Cut down pickup
1948 Ford F2 pickup
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Dan Hatch
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Re: Autolite spark plug number
Terry what color are the bases on your A-25? They are take apart right?
I have some I got in the 60’s that are cad plated. The 50’s ones I got are black or blued. Dan
I have some I got in the 60’s that are cad plated. The 50’s ones I got are black or blued. Dan
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ModelTWoods
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TXGOAT2
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Re: Autolite spark plug number
I've had a few of the terminals come loose from the insulator. I don't remember exactly what plugs they were. My car has "Silvery plated" Champion A 25 plugs in it. They have performed very well for over 15,000 miles.
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Tmooreheadf
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Re: Autolite spark plug number
Anyone had trouble with 3095 plugs leaking compression at the top metal crimp where it contacts the porcelain on the OD?
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TXGOAT2
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Re: Autolite spark plug number
Are you sure it's a compression leak? Leaks at that point are unusual. Gray to black deposits are common on plug insulators, especially where rubber boots are used on the plug wires. It's caused by high voltage corona and will usually wipe off easily.