What does chopping the spark plug do

[evaneyeball]

Just wondering what chopping the sparkplug is and what does it do or tell you. I've heard people talk about it on draft applications.

[The norm]

A plug chop will tell you if your jetting is too rich, too lean, or just right lol.
This is how I do it. Probably not the text book version....
What you do is warm your engine.... Swap to a new plug and take off and get rolling. Pin it to win it while banging gears through 4th. Then kill the engine while at wfo. Pull your plug and put in the old one you warmed it up with. Ride back to camp and have a tasty pbr. Take a flashlight and look down in to the plug. If it's white you are very lean.... If it's black you are very rich. If it's a golden brown its just right. Some people cut the threaded portion of the plug off to see the ceramic better, but I can't afford to waste a $3.00 plug because of all the pbr I like to enjoy.

[Michael88R]

Evan, skip the Pbr step for another 8 years.  😂.

[The norm]

Oh yeah lol! Add Mountain Dew to that step lol

[evaneyeball]

thanks i was just wondering. what it was for. i had heard about people chopping plugs on drag bikes. and even if i did have to do this i couldent last time i rode it. i admidantly chickened out in 4th gear. sand was too choppy. thats my excuse for now. dang it no beer, ok mom. lol

[evaneyeball]

Very helpful thanks

[havinnoj]

I will add that it's really only useful on the main jet circuit. 

[Jerry Hall]

Years ago I was also misguided by the myths and folklore that has been passed down over the generations.  I have also read may of these myths on this site.  Being an engineer has caused me to question and try to understand why these myths exist and why past generations have come to their conclusions from reading spark plugs.

I am sorry that I do not have the time to keep answering these same common questions.

I think than I have posted on this site more than once, what I have learned about reading spark plugs during my 45 + years of designing, modifying existing designs, and testing two stroke engines.  You guys would be amazed at the size of the mountain it would create if I could put all of the destroyed cylinders, heads, engine cases, exhaust systems etc. in one pile that it took to learn what I know about two strokes.

Someone please do a search on this site and or on other sites and read what  I have learned/published about reading spark plugs.  It does not agree with a lot of the folklore/myths that has been published in books and the internet over the last 50 years or so. 

I will by happy to defend my answers and answer specific questions about these myths and what specific observations are revealing to the person reading the spark plug. 

[2ndmoto]

Seems like should be a sticky...if there isn't already one.

[croat1]

Read through these threads

https://www.forums.trx250r.org/index.php/topic,2674.msg26488.html#msg26488

https://www.forums.trx250r.org/index.php/topic,5931.msg55536.html#msg55536

[havinnoj]

Seems like should be a sticky...if there isn't already one.

I will make it one.

Read through these threads

https://www.forums.trx250r.org/index.php/topic,2674.msg26488.html#msg26488

https://www.forums.trx250r.org/index.php/topic,5931.msg55536.html#msg55536

Thanks for linking these here Joe!