Spark Plug Colour

[Jack Klarich]

Well somebody is probably going to say I'm just to old school but I will put my .02c in anyway. Here is the way I was taught to read a sparkplug when I was racing motocross. First install new plug(s). Next run the bike up to 50 to 60mph, and hold it steady for 5 to 10 min. Next chop the throttle closed pull in the clutch and turn off ignition and bring the bike to a quick stop. Remove the plugs quickly and read, you're looking for tan and no deposits. I have also read recently from a "wise" member here on the forum, that with the introduction of ethanol it is almost impossible to get a good read on plugs no matter how you do it.

With an eye loop and a good light you can still read the heat rings on the plug, it is a lot harder now with out the lead that added color to the plug

 

[Wlindsey]

Well somebody is probably going to say I'm just to old school but I will put my .02c in anyway. Here is the way I was taught to read a sparkplug when I was racing motocross. First install new plug(s). Next run the bike up to 50 to 60mph, and hold it steady for 5 to 10 min. Next chop the throttle closed pull in the clutch and turn off ignition and bring the bike to a quick stop. Remove the plugs quickly and read, you're looking for tan and no deposits. I have also read recently from a "wise" member here on the forum, that with the introduction of ethanol it is almost impossible to get a good read on plugs no matter how you do it.

Second that Don That is the way I always got my plug readings on my race outboards. Don't know if it is wrong or right but I never melted one down that way.

 

[Jack Klarich]

Here is what I look for with a light and an eye loop, take note of at least 3 threads to have some coloration

 

[HDDon]

Second that Don That is the way I always got my plug readings on my race outboards. Don't know if it is wrong or right but I never melted one down that way.

I raced APBA for 8 years. Always outboard class, stock and Alcohol. Mostly Anzani, and Konig. All Mercury in the stock classes.

 

[dolt]

The only way to get true plug readings is with new plugs. You need to test as HDDon lays out. Start with several sets; get the motor to operating temp and run at a steady speed for a while and close throttle, shut down and coast to a stop to pull plugs. Install fresh plugs, fire up and run through the gears hard, near rev limiter. When near rev limit in 4th, close throttle, shut down and pull plug for a WOT reading. Very likely you will see two different colors, or not, depending on jetting. The color of the plugs shown looks pretty good, a tad rich for my taste but I would want to see "true" plug readings before making any tuning adjustments; there is more to plug reading than the color of the insulator cone. The "base" ring color will tell you something as will the color change on the electrode will tell you something about timing and heat range. Google plug reading and red some more.

 

[propflux01]

Sounds like a plan. Ill get some new ones and go from there.