Read Sparkplugs
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
And ???? how many miles on the motor.....and what type of fuel are you using....and how do you have your timing set up....and does it 'ping' under hard acceleration...and are they gapped correctly and at what gap......and are you having any issues which causes you to pull them out and ask how they look???
DUB
DUB
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
It's virtually impossible to "read" plugs in street engines being run on modern fuels with ethanol additives - it's not like reading plugs back in the 60's when there was "real" gas. If you run race gas in the engine, you can read the plugs, but you will need a magnifying glass to see the tell-tale indicators on the nose. The best you can do is identify significant problems with oil burning in a cylinder or electrode erosion caused by detonation. Beyond that, you're not going to be "reading" plugs to get any useful tuning information.
Thread Starter
Melting Slicks
Joined: Sep 2016
Posts: 2,230
Likes: 982
From: Wauconda IL
And ???? how many miles on the motor.....and what type of fuel are you using....and how do you have your timing set up....and does it 'ping' under hard acceleration...and are they gapped correctly and at what gap......and are you having any issues which causes you to pull them out and ask how they look???
DUB
DUB
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Like mentioned earlier, can't determine fuel mixture from plugs.
For a street car looking at plugs will tell you if something is seriously out of whack, like burning a lot of oil, or choke is stuck closed or something.
Yours look fine.
For a street car looking at plugs will tell you if something is seriously out of whack, like burning a lot of oil, or choke is stuck closed or something.
Yours look fine.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
If you're interested in being able to read a spark plug for the purpose of honing your tune up, I suggest you get yourself an otoscope (cheap at around 50 bucks or thereabouts) and do some online research on reading plugs. Believe me, there's a ton of information out there and it's pretty consistent. The two things you're looking at when reading a plug is the ground strap for the blue line, which indicates your ignition timing, and the fuel line on the porcelain. These things still show up with modern gasoline and with a little knowledge and practice you can achieve some pretty good insight into your tune up. The 10-percent ethanol in fuels isn't enough to corrupt the readings. If you were running E-85, then you'd still read the ground electrode the same but the fuel mixture shows up at the base ring (where the threaded part ends) and the first two or three threads on the plug.
And if by "read", you really mean does anyone see some mechanical fault, like oil burning, being displayed on the plugs, then they look okay. But without a sharp focus and better lighting, it's always hard to say.
And if by "read", you really mean does anyone see some mechanical fault, like oil burning, being displayed on the plugs, then they look okay. But without a sharp focus and better lighting, it's always hard to say.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Here is a good plug reading article.
https://honda-tech.com/forums/forced...ug***-3063102/
Keep in mind you are reading all of the circuits, idle, cruise and WOT from a plug that has experienced all of those modes of operation.
https://honda-tech.com/forums/forced...ug***-3063102/
Keep in mind you are reading all of the circuits, idle, cruise and WOT from a plug that has experienced all of those modes of operation.
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